is 15675 (2006): flow measurement of natural gas and fluid
TRANSCRIPT
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IS 15675 (2006): Flow measurement of natural gas and fluidby orifice plate meters [PGD 26: Weights and Measures]
IS 15675: 2(306
%!7Wmn
Indian Standard
FLOW MEASUREMENT OF NATURAL GAS AND
FLUIDS BY ORIFICE PLATE
ICS 75.1 60.30; 75.180.30
METERS
@ 61S 2006
BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
June 2006 Price Group 12
— —--—— ———..
Weights and Measures Sectional Committee, PG 26
FOREWORD
This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by theWeights and Measures Sectional Committee had been approved by the Production and GeneralEngineering Division Council.
This standard is taken-for measuring the gas consumption at the bulk suppliers as well as at the users’end, when the gas is supplied through the pipelines. In order to meet the requirement of bulk supplierand large consumer, this standard has been formulated for accuracy of metering system and regulationof gas at different delivery point to fulfill the consumer satisfaction. This standard determines the flow bymeans of measurement of the differential pressure by orifice meter. The differential pressure is inducedby the flow of gas through a thin plate with a sharp square-edge-opening which is circular and concentricwith the pipeline. While measuring the flow rate, this standard indicates the differential pressure, gastemperature, “pressure density, viscosity etc.
In preparing the standard considerable assistance has been derived from the following publication:
“ISO 5167-2:2003 ‘Measurement of fluid flow by means of pressure differential devices inserted incircular-cross section conduits running full — Part 2: Orifice plates’
AGA 3 ‘American Gas Authority Report for Orifice Plate Meters’
Wherever comma (,) has been given in a formula or table in between numerals, it should be read asdecimal (.) mark.
Annexes A, B are for information only.
For the purpose of deciding whether a particular requirement of this standard is complied with, the finalvalue, observed or calculated expressing the result of a test or analysis, shall be rounded off in accordancewith IS 2:1960 ‘Rules for rounding off numerical values (revkecf)’. The number of significant placesretained in the rounded off value should be the same as that of the specified value in this standard.
IS 15675:2006
CONTENTS
Title
1. SCOPE
2. REFERENCE
3. PRINCIPLE OF THE METHOD OF MEASU~EMENT AND COMPUTATION
4. SYMBOLS/N• MENCLATUFIE
5. DESCRIPTIONS AND REQUIREMENTS
6. METER TUBE
7. MATERIALS
8. PRESSURE MEASUREMENT
9. PRESSURE TAPPINGS
10. COEFFICIENTS AND CORRESPONDING UNCERTAINTIES OF ORIFICE PLATES
11. INSTALLATION REQUIREMENTS
12. FLOW CONDITIONERS
13. MARKING
ANNEX A TABLES OF DISCHARGE COEFFICIENTS AND EXPANSIBILITY (EXPANSION)
FAOTORS
ANNEX B FLOW CONDITIONERS
Page
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i
IS 15675:2006
Indian Standard
FLOW MEASUREMENT OF NATURAL GAS AND
FLUIDS BY ORIFICE PLATE METERS
1 SCOPE
1.1 This standard specifies the geometry andmethod of use (installation and operatingconditions) of orifice plates when they are insertedin a conduit running full to determine the flow rateof the fluid flowing in the conduit. This standardalso provides background information for calculatingthe flow rate and is applicable in conjunction withthe requirements.
1.2 This standard is applicable to primary deviceshaving an orifice plate used with flange pressuretappings. Other pressure tappings such as venacontracta and pipe tappings used with orifice platesare not covered by this standard. This standard isapplicable only to a flow which remains subsonicthroughout the measuring section and where thefluid can be considered as single phase. It is notapplicable to the measurement of pulsating flow.It does not cover the use of orifice plates in pipesizes less than 50 mm or more than 1 000 mm, orfor pipe Reynolds number below 5000.
1.3 This standard is used for custody transfer ofnatural gas and fluids.
2 REFERENCE .
The following standard is indispensable for theapplication of this standard. For dated references,only the edition cited applies. For undatedreferences, the latest edition of the referencedstandard (including any amendment) applies.
Standard No.
ISO 5167-1:2003
Title
Measurement of fluid flow bymeans of pressure differentialdevices inserted in circular-cross section conduits runningfull — Part 1: General principlesand requirements
3 PRINCIPLE OF THE METHOD OFMEASUREMENT AND COMPUTATION
3.1 The principle of the method of measurementis based on the installation of an orifice plate intoa pipeline in which a fluid is running full. The
presence of the orifice plate causes a staticpressure difference between the upstream and
downst~eam sides .of the plate. The mass flow rate,qmcan be determined as follows:
‘“= J+ ‘:d’@=where p is the fluid density at the temperature andpressure for which volume is stated.
3.2 The uncertainty limits can be calculatedusing the procedure given in 8 of ISO 5167-1.Computation of the mass flow rate, which is apurely arithmetic process, can be performed byreplacing the different terms on the right hand sideof the above equation by their numerical values.
Similarly, the value of volume flow rate, qv iscalculated from:
qv=~P
where p is the fluid density at the temperatureandpressure for which the volume is stated.
The coefficient of discharge, C, is dependent onthe Reynolds number, f?., which is itselfdependent on qmand is to be obtained by iteration(see Annex A of ISO 5167-1) for guidanceregarding the choice of the iteration procedureand initial estimates.
3.3 The diameters d and D merrtioned in theformula are the values of the diameters at workingconditions. Measurements taken at any otherconditions shall be corrected for any possibleexpansion or contraction of the orifice plate andthe pipe due to the values of the temperature andpressure of the fluid during the measurement.
It is necessary to know the density and theviscosity of the fluid at the working conditions.In the case of a compressible fluid, it is alsonecessary to know the isentropic exponent ofthe fluid at working conditions.
4 SYMBOLS/NOMENCLATURE
This standard reflects orifice meter application tofluid flow measurement with symbols in generaltechnical use. Following symbols have been usedin this standard.
1
IS 15675:2006
Symbol
A
ccd(/=~ ;
AC (F7)/C :
d
d.
d,
D
D
DL
D.
Dn
D,
e
E
f
“cINPS
AP
APavg
APrm~
APd
P,
“R
Q“
G?w
F?a
R,
~
T.
<
Represented Quantity
speed-of-sound
orifice plate discharge coefficient
flange tap orifice plate dischargecoefficient
percent difference between baselineCd and installation effect Cd
orifice plate bore diameter calculatedat flowing temperature, ~
orifice plate bore diameter measuredat temperature, T~
orifice plate bore diameter calculatedat reference temperature, ~
meter tube internal diametercalculated at flowing temperature, ~
published meter tube internal pipediameter
meter tube length downstream oforifice plate in multiple of publishedinternal pipe diameters
meter tube internal diametermeasured at T.
nominal pipe diameter
meter tube internal diameter calculatedat reference temperature, ~
orifice plate bore thickness
orifice plate thickness
frequency
temperature in degrees Centigrade
recommended length of gauge line
nominal pipe size
orifice plate differential pressure
average orifice plate differentialpressure
root mean square of the fluctuatingdifferential pressure
instantaneous orifice platedifferential pressure
static pressure of the fluid at thepressure tap
temperature in degrees Rankine
volume flow rate
mass flow rate
absolute roughness average
Reynolds number
temperature of fluid at flowingconditions
temperature of the orifice plate and/or meter tube at time of diametermeasurements
reference temperature (450C) of
Symbol
UL1
ULZ
a
al
%
P
Pm
P,
&
6
P
Represented Quantity
orifice plate bore diameter and/ormeter tube internal diameter
UL - U~
meter tube length ( UL) from flowconditioner exit to orifice plate inmultiples of published internal pipediameters
linear c-oefficient of thermalexpansion
linear coefficient of thermalexpansion of the orifice plate material
Iinearcoefficient of thermal expansionof the meter tube material
ratio of ‘orifice plate bore to metertube internal diameter (cl/D)calculated atflowing temperature, ~
ratio of orifice plate bore to metertube internal diameter (drn/DJcalculated at temperature, T~
ratio of oriice plate bore to meter tubeinternal diameter (d/D) calculated atreference temperature, ~
orifice plate bore eccentricity
orifice plate bevel angle
fluid density
5 DESCRIPTIONS AND REQUIREMENTS
The descriptions are given to emphasize theparticular meaning of the terms as used in thisstandard.
5.1 Orifice Plate
The primary element is defined as the orifice plate,the orifice plate holder with its associateddifferential pressure sensing taps, the meter tube,and flow conditioner, if used.
5.2 General
The axial plane cross-section and -symbols of astandard orifice plate is shown in Fig. 1,2,3 and 4.
Care shall be taken in the design of the orifice plateand its installation to ensure that plastic bucklingand elastic deformation of the plate, due to themagnitude of the differential pressure or of any otherstress, do not cause the slope of the straight line toexceed 1 percent under working conditions.
5.3 General Shape
The part of the plate inside the pipe shall be circularand concentric with the pipe centre line. The facesof the plate shall always be flat and parallel.
The orifice plate is defined as a thin square-edgedplate with a mechanical circular bore, concentricwith the meter tube ID, when installed.
2
-Is 15675:2006
MARK INLET ON / ; IPADDLE TYPE llATES ~ :
I
- E
[ ;:‘
w,
~’ BEVEL ANGLE‘ (Lfi”ils”)
r
e
&.j -
~, BEVEL ANGLE
*’ (45; 15”)\
MARK OUTLET ON
< ORIFICE FITTING PLATES
FIG. 1 SYMBOLS FOR ORIFICE PLATE DIMENSIONS
t-ORIFICE PLATE OUTSIDE DIAMETER
PIPE INSI~J
pARALLEL BAR
ORIFICE BORE dm . DEPARTURE FROMFLATNESS
MAXIMUM ALLOWABLE DEPARTURE FROM FLATNESS= 0005 (Dm-dm )
FIG. 2 ORIFICE PLATE DEPARTURE FROM FLATNESS
(MEASURED AT EDGE OF ORIFICE BORE AND WITHIN INSIDE PIPE DIAMETER)
ORIFICE PLATE OUTSIDE DIAM TER
., _m . MAK t
%“ I
IPERPENDIcULARPARRALLEL BAR(.3)
FIG. 3 ALTERNATE METHOD FOR DETERMINATION OF ORIFICE PLATE DEPARTURE FROM FLATNESS
(DEPARTURE FROM FLATNESS = h, - /?l)
3
IS 15675:2006
I I I I I Ih
-Rug
FIG. 4 MAXIMUM ORIFICE PLATE DEPARTURE FROM FLATNESS
5.4 Orifice Plate Faces
The upstream and downstream faces of the orificeplate shall be flat. Deviations from flatness on theorifice pIate of less than or equal to 1 percent ofdam height (that is, 0.025 mm per mm of damheight) under non-flowing conditions are allowed.The dam height.can be calculated from the formula(D~ - dJ/2.This critericm for flatness applies to anytwo points on the orifice plate within the dimensionsof the inside diameter of the pipe. The departurefrom flatness is illustrated in Fig. 1,2 and 3.
The surface roughness of the upstream anddownstream faces of the orifice plate shall fiaveno abrasions or scratches visible to the naked eyethat exceeds 1.25 microns R,.
The orifice plate surface roughness may be verifiedby using an electronic-averaging-type surfaceroughness instrument with a cutoff value of not lessthan 0.75 mm. Other sudace roughness devices(for example, a visual comparator) are acceptablefor determining orifice plate surface roughness, ifthe same repeatability and reproducibility as thoseof the electronic-averaging-type surface roughnessinstrument can be demonstrated.
Due care shall be exercised to keep the plate cleanand free from accumulation of dirt, ice, grit, grease,oil, free liquid and other extraneous materials, tothe extent feasible, by instituting a regularinspection schedule (daily, weekly, monthly,quarterly, etc, depending on the serviceconditions). Damage and/or accumulation ofextraneous materials on the orifice plate may resultin a greater uncertainty for the orifice platecoefficient of discharge [Cd (/7)]. After anyinspection of the plate, it shall be thoroughlycleaned (free from accumulations as statedabove) prior to being placed back in service.
5.5 Roughness Average (RJ
The roughness average (l?J used in this standardis the arithmetic average of the absolute values ofthe measured profile height deviation taken within
the sampling length and measured from thegraphical centreline of the surface profile.
5.6 Thickness E and e
The thickness e of the orifice shall be between0.905D and 0.02D.
5.6.1 The difference between the values ofe measured at any point on the orifice shall not begreater than 0.001 D.
The thickness E of the plate shall be between eand 0.05D.
However, when 50 mm < D <64 mm, a thicknessE up to 3.2 mm is acceptable.
[f D 2200 mm, the difference between the valuesof E measured at any.point of the plate shall not begreater than 0.001 D. If D c 200 mm, the differencebetween the values of E measured at any point ofthe plate shall not be greater than 0.2 mm.
5.6.2 The inside surface of the orifice plate boreshall be in the form of a constant-diameter cylinderhaving no defects, such as grooves, ridges, pits,or lumps, visible to the naked eyes. The length ofthe cylinder is the orifice plate bore thickness (e).
The minimum allowable orifice plate borethickness (e) is defined by e 20.01 d,or e >0.125,whichever is larger.
The maximum allowable value of the orifice platebore thickness (e) is defined by e < 0.02D, ore s 0.125d, whichever is smaller, but e shall notbe greater than the maximum allowable orificeplate thickness (E).
5.6.3 The minimum, maximum, and recommendedvalues of orifice plate thickness (E) for types 304and 316 stainless steel orifice plates are given inTable 1.
5.6.4 Maximum allowable differential pressures forthe recommended orifice plate thickness given inTable 3 are for operating temperatures notexceeding 65”C, the orifice plate and/or holdingdevice manufacturer shall be contacted for specific
4
IS 15675:2006
Table 1 Orifice Plate Thickness and Maximum Allowable Differential PressureBased on the Structural Limit
(C/auses 5.6.3,5 .6.5,5.6.6 and 5.8)
Orifice Plate Thickness, E Maximum Allowable AP(Water Column) I
NominalJipe Size
(NPs)
mm
InsidePipe
Diameter
mm
mm
Minimum Maximum Recommended Orifice Fitting Orifice Flange
(1) (2)
42.85
49.25
52.50
58.42
66.65
73.66
77.93
(3)
2.92
2.92
2.92
2.92
2.92
2.92
2.92
(4)
3.30
3.30
3.30
(5)
3.78
3.18
3.18
(6) (7)
50.80
76.20
101.60
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
3.30
3.30
3.30
3.30
3.18
3.18
3.18
3.18
1000
1000
1000
1000
I80.06
87.33
97.18
102.26
2.92
2.92
2.92
2.92
3.30
3.30
3.30
3.30
3.18
3.18
3.18
3.18
1000
1000
1000
1000
345
345
345
345
1000
1000
1000
152.40 124.38
131.75
146.33
154.05
2.92
2.92
2.92
2.92
4.14
4.14
4.88
4.88
3.18
3.18
3.18
3.18
203.20 193.68
202.72
205.00
2.92
2.92
2.92
6.45
8.10
8.10
8.10
8.10
8.10
6.35
6.35
6.35
6.35
6.35
6.35
1000
1000
1000
1000I
254.00 242.87
254.51
257.45
288.90
303.23
307.09
2.92
2.92
2.92
570
570
570 -11000
1000
1000
1000
1000
304.80 4.45
4.45
4.45
9.63
10.11
10.11
12.45
12.70
12.70
6.35
6.35
6.35
285
285
285
406.40 373.08
381.00
381.64
4.45
4.45
4.45
9.53
9.53
9.53
465
465
465
1000
1000
1000
NOTES
1 Maximum allowable differential pressure is limited to 1000 min of water column which is the limit of the coefficient ofdischarge database.
2 Maximum allowable differential pressure is calculated for worst-case diameter ratio (typically P = 0.55-0.65).
‘3 The maximum differential pressure applies to stainless steel plates at a maximum temperature of 65”C, and for therecommended plate thickness.
4 For single-or dual-chamber fittings, the orifice plate seal ring was assumed to deflect under symmetric conditionswithout plastic deformation. As such, the effect on the seal ring was not investigated.
5 Especially at very high differential pressures, the user should carefully consider the associated thermodynamic effects,such as temperature change resulting from the Joule-Thompson effect as the stream passes through the orifice, and thelimits on AI?LPf, in particular, at low pressures. The sudden reduction of pressure will result in temperature and densitychanges.
5
IS 15675:2006
information on deflection for a given diameter ratio,temperature, orifice plate material, orifice plateholder, and differential pressure.
5.6.5 The use of an orifice plate thickness otherthan the recommended thickness is acceptable ineither new or existing orifice plate holding devicesas long as the thickness is within the maximumand minimum range shown in Table 1; and theorifice plate eccentricity, bore thickness, differentialpressure tap hole, and expansion-factor (see Table 2)pressure-ratio tolerances and limits are satisfied.
Table 2 Linear Coefficient ofThermal Expansion
SI Material Linear Coefficient ofNo. Thermal Expansion (a)
mm/mm “C
(1) (2) (3)
i) Type 304 and 316 0.00042291stainless steel
ii) Monel 0.000363474
iii) Carbon Steel 0.000283464
NOTE — Temperature conditions other than those stated inrefer to the American Society for Metals, Matals Handbook.
5.6.6 For incompressible fluids, the maximumdifferential pressure across the plate is limited bythe structural integrity of the fitting design. Themaximum differential pressure shall be limited tothose shown in Table 1. If the maximum differentialpressure is to exceed the limits specified, themanufacturer shall be consulted for allowablemaximum pressure for the fitting design. Inaddition, theflowimg conditions downstream of theorifice plate must remain above the local vapourpressure of the flowing fluid.
5.6.7 Orifice fitting manufacturers shall beconsulted to determine the maximum allowabledifferential pressure during the changing of orificeplates under flowing conditions. The high forcesassociated with using high differential pressures maymake it difficult to remove the plate, and may possibleresult in damage to the orifice plate or fitting.
5.6.8 The use of high differential pressures(AP/APf >18 mm of water-column where the AP)
is in cm of water at 50°C and P~is, in mm of water-column will result in expansion factor uncertaintiesin excess of 0.1 percent.
5.6.9 Operators shall be aware, for a given orificeplate size, that when there is a wide swing fromhigh to low flows, significant measurement errorswill occur during the low-flow period if the orificeplate remains unchanged. Generally, operationbetween 10 percent to-90 percent of the calibrated
differential span is considered good practice.Rangeability can also be increased using today’sdigital (electronic) transmitters. The effects on theaccuracy of transducers and/or transmitters usedfor wide range shall be evaluated versus savingson installation cost.
5.6.~0 For the full range of orifice plate thickness,the maximum allowable orifice plate diffe~emtialpressure can be obtained.
Higher differential pressures will result in highermeter-run gas velocities and higher permanentpressure losses. It is recommended that the gasvelocities be evaluated on an individual installationbasis for such things as noise, erosion, and thermowell vibration. The”meter run velocity is dependenton several different factors, and each individualuser will have different practices and limits onvelocity.
5.6.11 When the orifice plate thickness (E) exceedsthe orifice bore thickness (e), a bevel is required onthe downstream side of the orifice bore.
NOTE — Existing orifice plates, whossedge thickness meetsthe value defined by e c 0.033D~, need not to be rebeveledunless-reconditioning is required for other reasons.
For ease in machining, the next smaller values ofe ace 0.8 mm may be used.
5.6.12 Orifice plate bored that demonstrate anyconvergence from inlet to outlet are unacceptable.Bi-directional flow through an orifice plate with borethickness (e) that exceeds the limits specified inthis table is outside of the scope of this standard.
5.7 Angle of Bevel, a (see Fig. 1)
If the thickness Eof the plate exceeds the thicknesse of the orifice, the plate shall be beveled on thedownstream side. The beveled surface.shall be wellfinished. The angle of bevel a shall be 45° * 15°.
5.8 Orifice Plate Bore Diameter (d, d~, d,)
The calculated orifice pIate bore diameter (d) isthe internal diameter of the orifice plate measuringaperture (bore) computed at flowing temperature(TJ. The calculated orifice plate bore diameter (d)is used in the flow equation for the determ”inationof flow rate. The diameter (d) shall in all cases begreater than or equal to 12.5 mm. The diameterratio, d/D shall be always greater than or equalto 0.10 and less than equal to 0.75.
The measured orifice plate bore diameter (dJ isthe measured internal diameter of the orifice platemeasuring aperture at the temperature of theorifice plate (TJ at the time of bore diametermeasurements.
6
The reference orifice plate bore diameter (d,) isthe internal diameter of the orifice plate measuringaperture at reference temperature (T,), calculatedthe reference orifice plate bore diameter is thecertified or stamped orifice plate bore diameter.
The measured orifice bore diameter (dJ is definedas the mean (arithmetic average) of four or moreevenly spaced diameter measurements of the inletedge. None of the four or more diametermeasurements may vary from the mean value bymore than the tolerances given in Table 3.
Table 3 Roundness Tolerance for OrificePlate Bore Diameter, dm
(Clauses 5.6.4 and5.8)
SI Orifice Bore Diameter ToleranceNo. mm * mm
(1) (2) (3)
i) s 6.35’) 0.00762ii) 6.375 4-9.525’) 0.01016iii) 9.5504-1 2:7’) 0.0127iv) 12.7254-15.875 0.0127v) 15.9004-19.05 0.0127vi) 19.0754-22.225 0.0127vii) 22.2504-25.4 0.0127viii) >25.4 0.0127 mm
per mm of diameter
II use Of diameters below 11.43 mm is not prohibited, but
may results in uncertainties greater value.
The minimum, maximum, and recommended valuesof orifice plate thickness (f) for types 304 and 316stainless steel orifice plates are given in Table 1.
Maximum allowable differential pressures for therecommended orifice plate thickness given inTable 1 are for operating temperatures notexceeding 65°C, the orifice plate and/or holdingdevice manufacturer shall be contacted for specificinformation on deflection for a given diameter ratio,temperature, orifice plate material. Orifice plateholder, and differential pressure.
The use of an orifice plate thickness other thanthe recommended thickness is acceptable in eithernew or existing orifice plate holding devices as longas the thickness is within the maximum andminimum range shown in Table 1; and the orificeplate eccentricity, bore thickness, differentialpressure tap hole, and expansion-factor pressure-ratio tolerances and limits are satisfied.
For incompressible fluids, the maximum differentialpressure across the plate is limited by the structuralintegrity of the fitting design. The maximumdifferential pressure shall be limited to those shownin Table 1. if the maximum differential pressure is to
IS 15675:2006
exceed the limits specified, the manufacturer shallbe consulted for allowable maximum pressure forthe fitting design. In addition, the flowing conditionsdownstream of the orifice plate must remain abovethe local vapour pressure of the flowing fluid.
Orifice fitting manufacturers shall be consulted todetermine the maximum allowable differentialpressure during the changing of orifice plates underflowing conditions. The high forces associated withusing high differential pressures may make it difficultto remove the plate, and may possible -result indamage to the orifice plate or fitting.
The use of high differential pressures (AFYAPf>1-8 mmof water-column, where the AP is in mm of waterat 20”C and P! k in kg/m) will result in expansionfactor uncertainties in excess of 0.1 percent.
Operators shall be aware, for a given orifice platesize, that when there is a wide swing from high tolow flows, significant measurement errors willoccur during the low-flow period if the orifice plateremains unchanged. Generally, operation between10 percent to 90 percent of the calibrateddifferential span is considered good practice.Rangeability can also be increased using today’sdigital (electronic) transmitters. The effects on theaccuracy of transducers and/or transmitters us@forwide Tange shall be evaluated versus savingson installation cost.
For the full range of orifice plate thickness, themaximum allowable orifice plate differentialpressure can be applicable.
It is recommended that the gas velocities beevaluated on an individual installation basis”for suchthings as noise, erosion, and thermowell vibration.The meter-run velocity is dependent on severaldifferent factors, and each individual user will havedifferent practices and limits on velocity. Therefore,the allowable maximum differential pressures, do notconsider meter-run gas velocity. Higher differentialpressures will result in higher meter-run gas velocitiesand higher permanent pressure losses.
5.9 Orifice Plate Bore Edge
The upstream edge of the orifice plate bore shallbe square and sharp. The orifice plate bore edgeis considered too dull tor accurate flowmeasurement if the upstream edge reflects a beamof light when viewed without magnification or if theupstream edge shows a beam of light whenchecked with .an orifice edge gauge.
5.10 Orifice Plate Holder
The orifice plate holder is defined as a pressurecontaining piping element, such as a set of orifice
7
IS 15675:2006
flanges or an orifice fitting, used to contain andposition the orifice plate in the piping system.
6 METER TUBE
The meter tube is defined as the straight sectionof pipe, including all segments that are integral tothe orifice plate holder, upstream and downstreamof the orifice plate.
6.1 MeterTube Internal Diameter (D, Di, Dm, D,)
The calculated meter tube internal diameter (D) isthe inside diameter of the upstream section of themeter tube computed at flowing temperature (TJ Thecalculated meter tube internal diameter (D) is usedin the diameter ratio and Reynolds number equations.
The measured meter tube internal diameter (D~)is the average inside diameter of the upstreamsection of the meter tube measured 25 mmupstream of the adjacent face of the orifice plateand at the temperature of the meter tube (TJ atthe time of internal diameter measurements.
The reference meter tube internal diameter (D) isthe inside diameter of the upstream section of themeter tube calculated at the reference temperature( TJ. The reference meter tube internal diameter isthe certified meter tube internal diameter.
The upstream and downstream edges of the orificeplate bore shall be free from defects visible to thenaked eye, such .as flat spots, feathered texture,roughness, burrs, bumps, nicks, and notches.
If there is any doubt about whether the edge hassufficient quality for accurate-metering, the orificeplate shall be replaced.
The orifice plate temperature shall be recorded atthe time the bore diameter measurements aremade. These measurements shall be made underthermally stable conditicms; that is diameter atreference temperature ( Tr) and can be determinedusing the following equation:
dr=dm[l+al(~-~m)l
where
al = linear coefficient of thermal expansion forthe orifice plate material (see Table 2),
d, = orifice plate bore diameter calculated atreference temperature (T),
d~ = orifice plate bore.diameter measured at T~,
T~ = temperature of the orifice plate at time ofdiameter measurements, and
~ = reference temperature of the orifice platebore diameter.
NOTE — ccl,T~ and T, shall be in consistent units. For thepurpose of this standard T, is assumed to be ambienttemperature.
8
The orifice plate bore in diameter (d) calculatedat Tf is the reference diameter used to calculatethe bore diameter (dj at flowing conditions.
6.2 Diameter Ratio (p, p~, pr)
The diameter ratio (P) is defined as the calculatedorifice plate bore diameter (d) divided by thecalculated meter tube internal diameter (D).
The diameter ratio (PJ is defined as the measuredorifice plate bore diameter (dJ divided by themeasured meter tube internal diameter (DJ.
The diameter ratio (~) is defined as the referenceorifice plate bore diameter (d) divided by thereference meter tube internal diameter (D).
7 MATERIALS
7.1 The materials employed for gas meteringinstallation shall be capable of withstanding thegas composition under the all conditions that maybe experienced over the lifetime of the metering.
7.2 Any meter tube pipe not exceeding 600 mmdiameter shall be seamless wherever possible.Above this size, longitudinally S.A.W. (submergedarc welded) pipe shall be used.
7.3 The pipe shall be inspected internally toensure that it complies to the dimensional andsurface finish tolerances specified in AGA 3.
7.4 Flanges shall be manufactured form forgedsteel. The flanges in the vicinity of the orifice plateshall be match-bored to the pipe and also dwelled/retained in such a manner that there is no internalstep in the meter tube.
7.5 On orifice fittings, the internal diameter,surface finish, concentricity and position andcondition of the pressure tap holes shall becarefully manufactured and inspected to lSO/AGAor an equivalent standard. I7.6 The orifice plate shall be manufactured fromstainless steel plate. The petrology of the plateshould meet the requirements of AGA 3. The platemay be manufactured from any material and inany way provided that it is remains in accordancewith the forging description during the flowmeasurement.
8 PRESSURE MEASUREMENT
8.1 Tap Hole
A tap hole is a hole drilled radially in the wall of themeter -tube or through the orifice fitting andperpendicular to the centreline of the meter-tubeor orifice plate holder, the inside edge of which isflush and without any burrs.
- . . ..-—. —.—, —-_.___.. .,,. .._____ .=.- _Q ——.- .—. ._ .“
8.2 Flange Taps
Flange taps are a pair of tap holes positioned as
follows:
a)
b)
c)
Upstream tap centre is located 25.4 mmupstream of the nearest plate face;
Downstream tap centre is located 25.4 mmdownstream of the nearest plate face; and
Upstream and downstream taps must bein the same radial position.
8.3 Differential Pressure (AP, APa,g, APrm~,APt)
The differential pressure (AP) is the static pressuredifference measured between the upstream andthe downstream flange taps.
The average differential pressure (APJ is a timemean of the static pressure difference measuredbetween the upstream and the downstream flangetaps.
The instantaneous differential pressure (APJ is asingle measurement of APat any instance in time.
The roor mean square differential pressure(AP,Jis the square root of the sum of squares of the
difference between the instantaneous differentialpressure (APJ and the time mean differential (APavg).
8.4 Permanent Pressure Drop
The permanent pressure drop is significantbecause the energy has been lost to transport thefluid through the pipeline. Approximate values ofthe permanent pressure loss AP versus ~ ratio forthe concentric, square-edged, flange tapped orficemeter are given below:
P Losses as a percent of AP
0.20 950.30 900.40 850.50 750.60 650.70 500.75 45
Examp/e:
If the user chooses to use a ~ of 0.30 at APof 10000 mm of water column then the permanentpressure loss would be approximately 90 percentof 10000 mm of water column which is about9000 mm of water column (about 90 kPa).
If the user chooses to use a ~ of 0.50 at AP of2500 mm of water column, then the permanentpressure loss would be approximately 75 percentof 2500 mm of water column, which is about1875 mm of water column (about 90 kPa).
1S 15675:2006
8.5 Temperature Measurement (~, T~, T,)
The temperature ( TJ is the flowing fluid temperaturemeasured at the designated location.
In flow measurement, the temperature sensingdevice is inserted in the flowing stream to obtainthe flowing temperature. However, if the fluid velocityis higher than 25 percent of the fluid sound-speedat the point of measurement, corrections for theincrease in temperature due to dynamic effects willhave to be applied. Care shall be taken to ensurethat the temperature sensing elements are coupledto the flowing stream and not to the steel in the metaltube. This practice is recommended for all orificemeter installations. The sensed temperature isassumed to be static temperature of the flowing fluid.
The temperature (7J is the measured temperatureof the orifice plate and/or the meter tube at thetime of the diameter measurements.
The temperature (TJ is the reference temperatureused to determine the reference orifice plate borediameter (d) and/or the reference internal meter tubediameter (DJ
Maximum departure = [hs + hJ] - [hl + hz]from flatness 2
An estimation of suitable sharpness can be madeby comparing the orifice plate bore edge with Ihebore edge of a properly sharp reference orifice.plateof the same nominal diameter. The orifice plate boreedge being evaluated should feel and look the sameas the edge of the reference orifice plate.
8.6 Bi-directional Plates
8.6.1 If the orifice plate is intended to be used formeasuring reverse flows, the following requirementsshall be-ensured:
a)
b)
c)
d)
plate shall not be bevelled;
two faces shall comply with thespecifications for the upstream face;
thickness E of the plate shall be equal tothe thickness e of the orifice consequently,it maybe necessary to limit the differentialpressure to prevent plate distortion; and
two edges of the orifice shall comply withthe specifications for the upstream edge.
8.6.2 For orifice plates with D and D/2 tappings,two sets of upstream and downstream pressuretaps shall be provided and used according to thedirection of the flow.
8.6.3 Material and Manufacture
The plate may be manufactured from any materialand in any way, provided that it is and remains in
IS 15675:2006
accordance with the foregoing description duringthe flow measurements.
9 PRESSURE TAPPINGS
9.1 General
For each orifice plate, at least one upstreampressure tapping and one downstream pressuretapping shall be installed in one or other of thestandard locations, that is as D and 0/2, flange orcorner tappings.
A.single orifice plate maybe used with several setsof pressure tappings suitable for different types ofstandard orifice meters, but to avoid mutualinterference, several tappings on the same side ofthe orifice plate shall be offset by at least 30°
The location of the pressure tappings characterizesthe type of standard orifice meter.
9.2 Orifice Plate with D and D/2 Tappings orFlangeTappings
9.2.1 The spacing of a pressure tapping is thedistance between the centreline of the pressuretapping and the plane of a specified face of theorifice plate. When installing the pressure tappings,due account shall be taken of the thickness of thegaskets and/or sealing material.
9.2.2 For orifice plates with D and D/2 tappings(see Fig. 3), the spacing /1 of the upstreampressure tapping is nominally equal to D, but maybe between 0.9D and 1.1 D without altering thedischarge coefficient.
The spacing ~.of the downstream pressure tappingis nominally equal to 0.5D but may be betweenthe following values without altering the dischargecoefficient:
a) between 0.48Dand 0.52 Dwhen ~ < 0.6; and
b) between 0.49Dand 0.51 D when ~ >0.6.
Both /1 and /z spacings are measured from theupstream face of the orifice plate,
For orifice plates with flange’ tappings (see Fig. 5),the-spacing /1of the upstream pressure tapping isnominally 25.4 mm and is measured from theupstream face of the orifice plate.
The spacing /2of the downstream pressure tappingis nominally 25.4 mm and is measured from thedownstream face of the orifice plate.
These upstream and downstream spacings /1and/2 may be within the following ranges wifhoutaltering the discharge coefficient:
a) 25.4 mm: * 0.5 mm when /?> 0.6 andD< 150 mm; and
b) 25.4 mm: t* mm in all other cases, that is,/3S0.6,0r~ >0.6 but 150mm<D<1000 mm.
The centreline of the tapping shall meet the pipecentreline at an angle as near to 90° as possible,but in every case within 3° of the perpendicular.
At the point of break-through, the hole shall becircular. The edges shall be flush with the internalsurface of the pipe wall and as sharp as possible.To ensure the elimination of all burrs or wire edges
p 12C
●& ]!I ~ ,1, 1
DI I I
.— .— - .— -— .—.: +3z
I
2
Ild
KEY‘ i-l--
\d
1 D and 0/2 pressure tappings
2 flange tappings: d =/, = l; = (25.4 t 0.5) mm for/3> 0.6 and
a = direction of flow D< 150mm
b=l, =D*O.l D = (25.4 *1) mm for /.3< 0.6
c = IZ=0.5D* 0.2Dfor fls O.6 = (25.4*1) mm for P >0.6 and 150 mm
0.5D* O.l Dfor /3 =-0.6<D<1000mm
FIG. 5 SPACING OF PRESSURE TAPPING FOR ORIFICE PLATE WITH D AND D/2
TAPPING OR FLANGE TAPPINGS
10
at the inner edge, rounding is permitted but shallbe kept as small as possible and, where it can bemeasured, its radius shall be less than one-tenthof the pressure tapping diameter. No irregularityshall appear inside the connecting hole, on theedges of the hole drilled in the pipe wall or on thepipe wall close to the pressure tapping.
Conformity of the pressure tappings with therequirements specified at above and may bejudged by visual inspection.
The diameter of pressure tappings shall be lessthan 0.1 3D and less than 13 mm.
No restriction is placed on the minimum diameter,which is determined in practice by the need toprevent accidental blockage and to give satisfactorydynamic performance. The upstream anddownstream tappings shall have the same diameter.
The pressure tappings shall be circular andcylindrical over a length of at least 2,5 times theinternal diameter of the tapping, measured fromthe inner wall of the pipeline.
I
1
—.—
I2
IS 15675:2006
The centrelines of the pressure tappings may belocated in any axial plane of the pipeline.
The axis of the upstream tapping and that of thedownstream tapping may be located in differentaxial planes, but are normally located in the sameaxial plane.
9.3 Orifice Plate with Corner Tappings
9.3.1 The spacing between the centrelines of thetappings and the respective faces of the plate isequal to half the diameter or to half the width ofthe tappings themselves, so that the tapping holesbreak through the wall flush with the faces of theplate.
9.3.2 The pressure tappings maybe either singletappings or annular slots. Both types of tappingsmay be located either in the pipe or its flanges orin carrier rings as shown in Fig. 6.
The diameter a of a single tapping and the width aof annular slots are specified below. The minimumdiameter is determined in practice by the need toprevent accidental blockage and to give satisfactory
-5
II
1 — carrier ring with annular slot
2 — individual tappings
3 — pressure tappings
4— carrier ring
5 — orifice plate
x = direction of flow
f = thickness of the slot
c = length of upstream ring
c’ = length-of the downstream ring
b = diameter of the carrier ring
a = width of annular slot or diameter ofsingle tapping
s = distance from upstream step to carrierring
g. h = dimensions of the annular chamber
@j = chamber tapping diameter
-4@-FIG. 6 CORNER TAPPINGS
11
IS 15675:2006
dynamic performance. For clean fluids andvapours:
a) for P <0.65: 0.005D > a S 0.03G and
b) for ~ >0.65:0.01 DS a < 0.02D.
If D< 100 mm, a value of a up to 2mm isacceptable for any p.
For any values of ~:
a)
b)
c)
for clean fluids: 1 mm< a <10 mm;
for vapours, in the case of annularchambers: 1 mms as 10 mm; and
for vapours and for liquefied gases, in thecase of single tappings: 4 mm S as 10 mm.
The annular slots usually break through the pipeover the entire perimeter, with no break incontinuity. If not, each annular chamber shallconnect with the inside of the pipe by at least fouropenings, the axes of which are at equal anglesto one another and the individual opening area ofwhich is at least 12 m2.
If individual pressure tappings, as shown in Fig. 4,are used, the centreline of the tappings shall meetthe centreline of the pipe at an angle as near to90° as possible.
If there are several individual pressure tappings inthe same upstream or downstream plane, theircentrelines shall form equal angles with each other.
The pressure tappings shall be circular andcylindrical over a length of at least 2, 5 times theinternal diameter of the tappings measured fromthe inner wall of the pipeline.
The upstream and downstream pressure tappingsshall have the same diameter.
The internal diameter b of the carrier rings shallbe greater than or equal to the diameter D of thepipe, to ensure that they, do not protrude into thepipe, but shall be less than or equal to 1.04D.Moreover, the following condition shall be met
b- DXcX1w< 0.1
DD 0.1 + 2.3 ~’
The lengths c and c’ of the upstream anddownstream rings (see Fig. 6) shall not be greaterthan O.SD.
The thickness fof the slot shall be greater than orequal to twice the width of the annular slot. Thearea of the cross-section of the annular chamber,g~, shall be greater than or equal to half the totalarea of the opening connecting this chamber tothe inside of the pipe.
All surfaces of the ring that are in contact with the
measured fluid shall be clean and shall have awell-machined finish. The surface finish shall meetthe pipe roughness requirements.
The pressure tappings connecting the annularchambers to the secondary devices are pipe-walltappings, circular at the point of break-through andwith a diameter j between 4 mm and 10 mm.
The upstream and downstream carrier rings neednot necessarily be symmetrical in relation to eachother, but they shall both conform with the precedingrequirements.
The diameter of the pipe shall be measured, thecarrier ring being regarded as part of the primarydevice. This also applies to the distances shall bemeasured from the upstream edge of the recessformed by the carrier ring.
10 COEFFICIENTS AND CORRESPONDINGUNCERTAINTIES OF ORIFICE PLATES
10.1 Limits of Use
Standard orifice plates shall only be used inaccordance with ISO 5167-1 under the followingconditions.
For orifice plates with corner or with D and D/2pressure-tappings:
a) d> 12.5 mm;
b) 50mm<D<1000 mm;
c) 0.1sps0.75;
d) Re~S5000 for 0.1 s ~ < 0.56; .and
e) Re~2 16000 /32for ~ > C!.56.
For orifice plates with flange tappings:
a) d> 12.5 mm;
b) 50 mms D <1000 mm; and
c) 0.1<ps0.75.
Both f?e~25 000 and l?e~ 2170 j32D
where D is expressed in millimetres.
The pipe internal roughness shall satisfy thefollowing specification if the uncertainty values inthis part of ISO 5167-1 are to be met, L,. the valueof the arithmetical mean deviation of the roughnessprofile, R., shall be such that 104Ra/D is less than
the maximum value given in Table 4 and greaterthan the minimum value given in Table 5. Thedischarge coefficient-equation was determined froma database collected using pipes.whose roughnessis known; the limits on R.JD were determined sothat the shift in discharge coefficient due to using apipe of a different roughness should not be so greatthat the uncertainty value. Information regardingpipe roughness may be foundofISO5167-1.
I
12
1S15675 :2006
Table 4 Maximum Value of 104RJD
(C/ause 10.1)
SI P R]D
No.104 3X104 105 3 x ?05 10“ 3xloe 107 3X107 10“
(1) (2) (3) (4) (5) (6) (7) (8) (9) (lo) (11)
i) 0.20 15 15 15 15 15 15 15 15 15
ii) 0.30 15 15 15 15 15 15 15 14 13
iii) 0.40 15 15 10 7.2 5.2 4.1 3.5 3.1 2.7
iv) 0.50 11 7.7 4.9 3.3 2.2 1.6 1.3 1.1 0.9
v) 0.60 5.6 4.0 2.5 1.6 1.0 0.7 0.6 0.5 0.4
vi) 0.65 4.2 3.0 1.9 1.2 0.8 0.6 0.4 0.3 0.3
Table 5 Minimum Value of 104RJD (where One is Required)
(C/ause 10.1)
SI P RJDNo.
<3 X1O’ 107 3 x 107 108
(1) (2) (3) (4) (5) (6)
i) 50.50 0.0 0.0 0.0 0.0
ii) 0.60 0.0 0.0 0.003 0.004
iii) >0.65 0.0 0.013 0.016 “0.012
The roughness requirements relate to the orificefitting and the upstream pipe work. The downstreamroughnessis not as critical.
For example, the requirements of this section aresatisfied in either of the following cases:
lpm Sf?~S6pm, D2150mm, ~: <0.6 andF?e~s 5 x 107; and
l~ms F/, s6pm, D2150mm, j3:S0.6and
Re~<5x 107.
where D is less than 150 mm, it is necessary tocalculate the maximum arid minimum values of/?, by using Tables 6 and 7.
10.2 Coefficients
10.2.1 Discharge Coefficient, C
The discharge coefficient, C, is given by theReader-Harris/Gallagher (1998) equation:
C = 0.5961+ 0.0261~’ - 0.2~ 6P’
(),06 p 0’7
+0.000 521 —R%
* 0.3
()
+(0.01 88 + 0.0063A)f135 ~R%
+(0.043 + 0.080e-104 – O.123e”74 )
(l-O,llA)fi- 0.031 (M: - 0.8Mj’’)@’3
where D <71, 12 mm, the following term shall beadded to Equation:
‘001;(0075-421B-%In these equations
B (=d/D) — diameter ratio, with the diameters dand D expressed in millimetres;
Re~ — Reynolds number calculated withrespect to ~
L1(=ll/D) — quotient of the distance of theupstream tapping from theupstream face of the plate and thepipe diameter; and
L;(=/JD) — quotient of the distance ofthe downstream tapping from thedownstream face of the plate andthe pipe diameter (L; denotes thereference of the downstreamspacing from the downstream face,while L2 would denote thereference of the downstreamspacing from the upstream face).
1“3
IS 15675: 20Ci6
M;=%-1-p
()
~= 19000f3 0“8
Re.
The values of L, and L2 to be used in this equation,when the spacings are in accordance with therequirements of 5.2.2.2, 5.2.2.3 or 5.2.3 are asfollows:
— for corner tappings:
Ll=q=o— for D and D12 tappings:
Ll=l
L’, = 0.47
— for flange tappings:
254L1=L’2=~
where D is expressed in millimetres.
The Reader-Harris/Gallagher (1998) equation, isonly valid for tapping arrangements. In particular,it is not permitted to enter into the pairs of valuesL1 and L2 which do not match one of the threestandardized tapping arrangements.
The uncertainties are only valid when themeasurement meets all the limits of use and thegeneral installation requirements specified in 6 andin ISO 5167-1.
Values of C as a function of ~, Re~ and D. Thesevalues are not intended for precise interpolation.Extrapolation is not permitted.
10.2.2 -Expansibility (Expansion) Factor
For Ihe three types of tapping arrangement, theempirical formula [s] for computing the expansibility(expansion) factor, G is as follows:
[01
llk
E = 1 -(0.351+ 0.256~4 +0.93~a ) 1– ~PI
Equation is applicable only within the range of thelimits of use.
Test results for the determination of e are onlyknown for air, steam and natural gas. However,there is known objection for other gases andvapours of which the isentropicexponent is known.
Nonetheless, Equation is applicable only ifp2/pl 20.75.
Values of the expansibility (expansion) factor as afunction of the isentropic exponent, the pressure ratioand the diameter ratio.are given for convenience inTable 19, These values are not intended for preciseinterpolation. Extrapolation is not permitted.
10.3 Uncertainties
~0.3.1 Uncertainty of Discharge Coefficient, C
For all three types of tappings, when P D, Re~ andRJD are assumed to be known without error, therelative uncertainty of the value of C is equal-to:
a) (!3.7 -~) percent for 0.1 s ~ c 0.2;
b) 0.5 percent for 0.2 S/3< 0.6; and
c) 1,667 @-0.5 percent for 0.6< ~s -0.75.
If ~ >0.5 and Re~ <10000, the following relativeuncertainty shall be added arithmetically to theabove values.
10.3.2 Uncertainty of Expansibility (Expansion)Factoc c
When p, Ap/pl and k are assumed 10 be knownwithout error, the relative uncertainty of the valueof e is equal to:
3.5 ‘p~ percent
10.4 Pressure Loss, Am
10.4.1 The pressure loss, Ace,for the orifice platesdescribed in this part of ISO 5167-1 is approximatelyrelated to the differential pressure Ap by:
*W= J1-/34(l-c’)-c@*P
%1~ +Cp’
This pressure loss is the difference in staticpressure between the pressure measured at thewall on the upstream side of the orifice plate, at asection where the influence of the approach impactpressure adjacent to the plate is still negligible(approximately D upstream of the orifice plate),and that measured on the downstream side of theorifice plate, where the static pressure recoveryby expansion of the jet maybe considered as just,completed (approximately 6D downstream of theorifice plate). Figure 7 shows the pressure profilethrough an orifice metering system.
10.4.2 Another approximate value of AdAp is
:=1–P’.9
10.4.3 The pressure loss coefficient, K, for theorifice plate is
(
K= J~_12
Cp’ )where K is defined by the following equation:
K=#&
14
IS 15675:2006
“’lyl.1’5’
[%1’i112!3t -? 1 (1“ I
18!: I
=9
KEY1 — planeof upstream pressure
tappings2— plane of downstreampressure
tappings3 — plane of “vena contracta” (highest
velocities)4— plane of temperatureprobe5 — secondar-yflow regions6 — thermometer pocket or well7 — pressuretappings8 — pressuredistribution on the wall9— mean temperaturedistribution
FIG. 7 APROXIMATE PROFILES OF FLOW, PRESSURE AND TEMPERATURE
IN AN ORIFICE METERING SYSTEM
11 INSTALLATION REQUIREMENTS
11.1 General
General installation requirements for pressuredifferential devices are given in this standard andshall be followed in conjunction with the additionalspecific requirements for orifice plates. The generalrequirements for flow conditions at the primarydevice are also given in this standard. Therequirements for use of a flow conditioner are alsomentioned. A flow conditioner will permit the useof a shorter upstream pipe length; moreover, a flowconditioner shall be installed upstream of the orificeplate where sufficient straight length to achievethe desired level of uncertainty is not available.Downstream of a header the use of a flowconditioner is strongly recommended.
11.2 Minimum Upstream and DownstreamStraight Lengths for Installation BetweenVarious Fittings and the Orifice Plate
11.2.1 The minimum straight lengths of piperequired upstream and downstream of the orificeplate for the specified fittings in the installationwithout flow conditioners are given in Table 6.
11.2.2When a flow conditioner is not used, thelengths specified in Table 6 shall be regarded asthe minimum values. For research and calibrationwork in particular, =it is recommended that theupstream values specified in Table 6 be increasedby at least a factor of 2 to minimize the measurementuncertainty.
11.2.3 When the straight lengths used are equal
to or longer than the values specified in columnsA of Table 6 for ‘zero additional uncertainty’, it isnot necessary -to increase the uncertainty indischarge coefficient to take account of the effectof the particular installation.
11.2.4 When the upstream or downstream straightlength is shorter than the value corresponding to‘zero additional uncertainty’ shown in columns Aand either equal to or greater than the 0.5 percentadditional uncertainty value shown in columns B ofTable 6 for a given fitting, an additional uncertaintyof 0.5 percent shall be added arithmetically to theuncertainty in the discharge coefficient.
11.2.5This part of the standard cannot be usedto predict the value of any additional uncertaintywhen either:
a) straight lengths shorter than the0.5 percent additional uncertainty valuesspecified in columns B of Table 6 are used;or
b) “both the upstream and downstreamstraight lengths are shorter than the ‘zeroadditional uncertainty’ values specified incolumns A of Table 6.
11.2.6The value shown in Table 6 shall be set fullyopen during the flow measurement process. It isrecommended that control of the flow rate beachieved by valves located downstream of theorifice plate. Isolating valves located upstream ofthe orifice plate shall be set fully open, and thesevalves shall be full bore. The valve shall be fitted
15
Table 6 Required Straight Length Between Orifice Plates and Fittings Without Flow Conditioners
(C/auses 11.2.1,11.2.2,11.2.3, 11.2.4,11.2.5,11.2.6,11 .2.7 and 11 .2.8)
Values expressed as multiples of internal diameter, D
Down-stream
(outlet) sid,of the
orifice plat{
Upstream (inlet) side of orifice plate
Two 90”bends inpetpan-dicsdarplanes
(30;D7S >
5
Single 45°bend
Two 45’bends intha same
plane:S-configur-
ation
(S>2D)’
8
3iam-etsrratio
P 1Two 90°banda Iif
Two 90”
the samebands inthe same
planeS*onfigur-
planw
ationS-configur-
ation
(s:Dj: ‘ (IOD > S) a
3 4
Single 90”band
Two 90”bsrndainany plane
(s> 30D) a
Two 90° Single 90”bends in teewith orperpen- without andicular extension
Ther-Fuil bora mometerball valve Abrupt pocket
or gate aymmetricel or well cvalve fully reduction of diameter
open< 0,03D d
Concentricraducar2Dto Dover a
length of1,5D to 3D
Concentricexpander0,5D to D
over alength ofDto2D
Fittlnga(calumns 2toll) andthe densi-tometerpocket
planesMitre 90”
(5D>S)s, b bend
I11 12 139 10 146 171
+
Ae B’
19 18
44 46
Ae t B’ Ae I Bf Ae ~f Ae B’ Ae ~f,, Aa I Bf
4+-R-E- +
79
30 9
+
69
12 8
20 9
26 11
12 6 30 15 5 3
+
42
63
; 0,20
0,40 +
63
16 3 ww +
44 18
44 18 * +
30 18
30 18 +
85
95 +
63
7 3,5
0.50
+
22 9
42 130,60
0,57
* +
44 18
44 18 +
12 6
13 8 +
28 14
36 18
18 9 30 15 5 3
24 12 30 15 513+-
7 3,5
84+
44 20
44 20* +
44 20
44 200,75
OTE1 The minimumstraightlengthsrequiredare the lengthsbetweenvariws ritings locatedupstreamor downstreamof the orifice plateand the ofiw plate itself. Straightlengthsshall be measuredfrom tluwmetreamend of the cur’vedportionofthanearest(oronly)bendor of the teeor the downstreamendofthecurvedorconicalportionof the reduceror the expander.
OTE2 Wet of the bendson whichthe Iengthain this tableare bawd hada radiusof curvatureequalto I,5D.
Sis ffreseparationbetweenthe twobendsmeasuredfromthedownstreamendof the cinvedportionof the upstreambendto the upstreamendOfthe cutvedption of the downstreambend.
ThisIs nota god ups!reaminstallation:a flow conditionershouldbe usedwbersfmesible.
Theinstallationof thermometerpocketsor W& will notalter the requiredminimumupstreamstraightIangfhafor the ofherfittings.
A thermometerpocketor well of d=meter between0,03D and 0,13D may be installed providedthat the valuaa in CdumnaA snd B are increasedto 20 and 10 respectively.Such an installationia not, however,cbmmendad.
ColumnA fw eachfittinggiveslengthamrrespondingto two addiionai uncartain~ values(See11.2.3).
ColumnB fcr eachriftinggiveslengthscorrespondingto “0,5 % additionaluncartainv values(See 11.2.4).
Theatraiiht length in CoiumnA giveszerosdditiorialuncetilnty dataare notavailablefor shortarstraightlengthswhichcouldbe used10givethe requiredstraightlengthsfor ColumnB.
95Dis reouiradfor Re~> ix 106ifsc D.
—--—...—..- .. ,_____,.,._ -...-.a-. —- —.— . . . . . “..
with stops for alignment of the ball in the open
position. The valve shown in Table 6 is one which isof the same nominal diameter as the upstream pipe.
11.2.7 In the metering system, upstream valveswhich are match bored to the adjacent pipe workand are designed in such a manner that can beregarded as part of the metering pipe work lengthand do not need to have added lengths as in
Table 6 provided that when flow is being measuredthey are fully open.
11.2.8 The values given in Table 6 weredetermined experimentally with a very longstraight length of pipe upstream of the fitting inquestion so that the flow immediately upstreamof the fitting was considered as fully developedand swirl-free. Since in practice such conditionsare difficult to achieve, the following informationmay be used as a guide for normal installationpractice.
a) Several fittings of the type covered byTable 6, treating the combinations of 90°bends already covered by these tables asa single fitting, are placed in seriesupstream of the orifice plate (see Fig. 8).
b) In addition to the rule in (a) any fitting,treating any two consecutive 90° bends asa single fitting, shall be located at a distancefrom the orifice plate at least as great asthe distance given by the product of thepipe diameter at the orifice and the numberof diameters required between that fittingand an orifice plate of the same diameterratio in Table 6, regardless of the numberof fittings between that fitting and the orificeplate. The distance between the orificeplate and the fitting shall be measuredalong the pipe axis. If, for any upstream
1 2
c)
d)
IS 15675:2006
fitting, the distance meets this requirementusing the number of diameters incolumns B but not that in columns A thena 0.5 percent additional uncertainty shallbe added arithmetically to the dischargecoefficient uncertainty, but this additionaluncertainty shall not be added more thanonce under the -provisions of (a) and (b).
It is strongly recommended that a flowconditioner shall be installed downstreamof a metering system header (for example,one whose cross-section area isapproximately equal to 1.5 times thecross-sectional area of the operating flowmeter tubes) since there will always bedistortion of the flow profile and a highprobability -of swirl.
When the second (or more distant) fittingfrom the orifice is a combination of bends,then in applying Table 6 the separationbetween the bends is calculated as amultiple of the diameter of the bendsthemselves.
11.2.9 By way of example, three cases of theapplication of 11.2.8(a) and (b) are considered. Ineach case, 1 second fitting from the orifice plate istwo bends in perpendicular planes (the separationbetween the berrds is 10 times the diameter of thebends) and the orifice plate has diameter ratio 0.4.
If the first fitting is a full bore ball valve fully open[see Fig. 9 (a)], the distance between the valveand the orifice plate shall be at least 12D (fromTable 5) and that between the two bendsperpendicular planes and the valve shall beat least22D [from 11.2.8(a)]; the distance between thetwo trends in perpendicular planes and the orificeplate shall beat least 44D [from 11.2.8(b)].
3
/I
I--L-IL If+D-
12 3
11
28 D
KEY
1 — expander2 — full bore ball valve or gate
valve fully open
3 — orifice plate
FIG. 8 LAYOUT INCLUDING A FULL BORE VALVE FOR ~ = 0.6
17
IS 15675:2006
If the first fitting is a reducer from 2D to D over alength of 2D[see Fig. 9 (c)], the distance betweenthe reducer and the orifice plate shall be at least5D (from Table 6) and that between the two bendsin perpendicular planes and the reducer shall beat least 22 x 2D [from 11.2.8 (a)]; the distancebetween the bends in perpendicular planes andthe orifice plate shall be at least 44D. So noadditional length is required because of 11.2.8(b).
If the first fitting is an expander from 0.5D to Dover a length of 2D [see Fig. 9(d)], the distancebetween the expander and the orifice plate shallbe at least 12D (from Table 5) and that betweenthe bends in perpendicular planes and theexpander shall beat least 22x 0.5D [from 6.2.8 (a)];the distance between the two bends in perpendicularplanes and the orifice plate shall beat least 44D
[from 11.2.8 (b)]. So an additional total length of19D is required which may be either upstream ordownstream of the expanded partly upstream andpartly downstream of it.
12 FLOW CONDITIONERS
12.1 General
A flow conditioner can be used to reduce upstreamstraight lengths either through meeting thecompliance test given in this standard, in whichcase it can be used downstream of any upstreamfitting, or through meeting the requirements of thisstandard, which gives additional possibilitiesoutside compliance testing. In either case the testwork shall be carried out using orifice plates.
Unpatented flow conditioners which have met the
(22*X)D .0 (12*y)l)I
a) x >0, Yao, x+ya9
c)
-FIG. 9 EXAMPLESOF ACCEPTABLElNSTALLATtON
18
—.
compliance test of this standard are the 19-tubebundle flow straightener (1998) and the Zankerflowconditioner plate. Annex B describes some patentedflow conditioners which have met the compliancetest. Clause 12.2 and 12.6 give the situations inwhich the 19-tube bundle flow straightener (1998)and the Zanker flow conditioner plate can be usedupstream of orifice plates. Clause 12.4 and 12.6.2describe the situations in which the 19-tube bundleflow straightener (1 998) and the Zanker flowconditioner plate can be used downstream of anyfitting. Clause 12.5 describes some additionalsituations in which the 19-tube bundle flowstraightener (1998)] may be used to reduce therequired upstream length. Annex B describes someflow conditioners which can be used upstream oforifice plates and the requirements for straightlengths associated with them. It is not intended thatthe inclusion of the flow conditioners described thereshould limit the use of other flow conditioner designswhich have been tested and proved to providesufficiently small shifts in discharge coefficient.
12.2 19-Tube Bundle Flow Straightener (1998)
The 19-tube bundle flow straightener (1998) shallconsist of 19 tubes arranged in a cylindrical patternas in Fig. 10.
In order to reduce the swirl that can occurbetween the exterior tubes of the 19-tube bundleflow straightener (1998) and the wall of the pipe,
A
IS 15675:2006
the maximum outside diameter of the flowstraightener, Dt shall satisfy
0.95D s D, s D
The length, L, of the tubes shall be between 2Dand 3D, preferably as close to 2D as possible.
12.2.1 Description
12.2.2 Design
12.3 Tubing of the 19-Tube Bundle FlowStraightener (1998)
All the tubes in the tube bundle shall be of uniformsmoothness, outer diameter and wall thickness.The individual tube wall thickness of the 19-tubebundle flow straightener (1998) shall be thin. Alltubes shall have an internal chamfer on both ends.
The wall thickness shall be less than 0.0250 thisvalue is based on the wall thickness of the tubesused to collect the data on which this standard isbased.
12.3.1 Fabrication of the 19-Tube Bundle FlowStraightener (1998)
The 19-tube bundle flow straightener (1998) shallbe sturdily fabricated. Individual tubes shall bewelded together at the points of contact, at leastat both ends of the tube bundle. It is important toensure that the tubes are parallel to each otherand to the pipe axis since, if compliance with this
2
3
KEY
1 — minimized gap2 — pipe wall3— tube wall thickness4— centring spacer options (typically four places)
d Df = flow straightener outside diameter
I 1
F=====it
.. -—--- ------ —--— I1, I
FIG. 10 FABRICATION OF THE 19-TUBE BUNDLE FLOW %RAtGHTENER (1998)
19
IS 15675:2006
requirement is not met, the straightener”itself may
introduce swirl into the flow. Centring spacers may
be provided on the outside of the assembly to
assist the installer in centring the device in the pipe;these may take the form of small lugs small rodsparallel to the pipe axis. After being inserted in thepipe, the -tube bundle shall be securely fastenedin place. Secure fastening, however, should notdistort the tube bundle assembly with respect tosymmetry within the pipe.
12.3.2 Pressure Loss
The pressure loss coefficient, K, for the 19-tubebundle flow straightener (1998) is approximatelyequal to 0.75, where K is given by the folIowingequation:
where
APC = pressure loss across the 19-tube bundleflow straightener (1998);
P = density of the fluid in the pipe; and
v = mean axial velocity of the fluid in thepipe.
12.4 lns-tallation Downstream of Any Fitting
12.4.1 The 19-tube bundle flow straightener(1 998) shown in Fig. 10 can be used downstreamof any upstream fitting with an orifice plate whosediameter ratio is 0.67 or smaller provided that itmeets the manufacturing specification and isinstalled in accordance with specific clause.
12.4.2 The 19-tube bundle flow straightener(1 998) shall be installed so that the distancebetween the downstream end of the 19-tubebundle flow straightener (1 998) and the orificeplate is equal to 13D * 0,25D.
12.5 Additional Options
12.5.1 A 19-tube bundle flow .straightener (1 998)may also be used to reduce the required upstreamstraight length in situations outside the situationas described in respective clause. The 19-tubebundle flow straightener (1998) shall be asdescribed in specific clause.
The permitted locations for the 19-tube bundle flowstraightener (1998) depend on <, the distance fromthe orifice plate to the nearest upstream fitting,measured to the downstream end of the curvedportion of the nearest (or only) bend or of the teeor the downstream end of the curved or conicalportion of the reducer or expander.
Table 7 provides the permitted location range and
the-recommended location for the 19-tube bundleflow straightener (1998) for two ranges of ~:
a) 30D > ~ 2 18D, and
b) ~ 230D.
~ shall be greater than or equal to 18D.The locationsfor the 19-tube bundle flow straightener (1998) aredescribed in Table 7 in terms of the straight lengthsbetween the downstream end of the 19-tube bundleflow straightener (1998) and the orifice plate.
If, for a particular upstream fitting, an orifice platediameter ratio and a value of ~, there is no locationshown in Table 7 for a 19-tube bundle flowstraightener (1998), then an installation with thisfitting, ~ and ~, is not recommended. In this case,an increase in ~ and/or a reduction in ~ is necessaty.
The length required downstream of the orifice plateshall be as given m Table 6.
An example of the use of Table 7 is given in therespective clause.
12.5.2 When the straight length between orifice plateand 19-tube bundle flow straightener (1998) is inaccordance with the values specified in columns Aof Table 6 and the downstream straight length inaccordance with columns A of Table 7 for ‘zeroadditional uncertainty’, it is not necessary to increasethe uncertainty in discharge coefficient to takeaccount of the effect of the particular installation.
12.5.3 An additional uncertainty of 0.5 percentshall be added arithmetically to the uncertainty inthe discharge coefficient when either:
a) the straight length between orifice plate and19-tube bundle flow straightener (1 998)is not in accordance with the valuecorresponding to ‘zero additionaluncertainty’ shown in columns A but inaccordance with the value corresponding“to ‘0.5 percent additional uncertainty’ shownin columns B of Table 7; or
b) the downstream straight length is shorter thanthe value corresponding to ‘zero additionaluncertainty’ shown in columns A but eitherequal to or greater than the ‘0.5 percentadditional uncertainty’ value shown incoiumns B of Table 6 for a given f itting.
12.5.4 This standard shall not be used to predictthe value-of any additional uncertainty when:
a) the straight length -between orifice plateand 19-tube bundle flow straightener(4998) is not in accordance with the valuecorresponding to 0.5 percent additionaluncertainty shown in columns B of Table 7;or
20
.
N
Table 7 Permitted Range of Straight Lt?ngths Between an Orifice Plate and a 19-Tube Bundle Flow Straightener (1998)Downstream of Fittings Located at a Distance, ~, from the Orifice Plate
(C/auses 12.5.1,12.5.2,12.5.3, 12.5.4 and 12.5.5)
Values expressed as multiples of internal diameter, D
DiameterTwo 90” behds b in perpendicular planes
Single 90” bend b Single 90” tee Any fitthgmtio (ZD>$’
P 30> L-,218 Lf & 30 30> Lf>18 Lf a 30 30> Lfz18 Lf a 30 30> Lf318 Lf >30
1 2 3 4 5 6 7 8 9
— Ac Bd Ac Bd Ac Bd Ac Bd Ac Bd Ac Bd Ac Bd Ac Bd
<0,2 5 to 14,5 ItOne 5 to 25 ItOne 5 to 14,5 ItOne 5 to 2!5 ltOne 5 to 14,5 ItOne 1 to 25 ItOne 5toll ltone 5to13 ltone
0,4 5 to 14,5 ltone 5 to 25 ItOne 5 to 14,5 ltOne 5 to 25 ItOne 5 to 14,5 ItOne 1 to 25 ItOne 5toll ltone 5to13 ItOne
0,511,5
3tOne11,5
3tone9,5
to 14,5ltone 9 to 25 ItOne ltorfe ltone fg
11,5
to 25 to 14,5llto13 9 to 23 3torre
to 14,53 tone
0,6 12to 13 5tone 12t025 Stone13,5
to 14,56t0ne 9 to 25 ItOne fh 7tone llto16 ~tone f 7torre 12to t6 6tone
0,67 13 7tone13
7tone13
7tone 10to16 5t0ne f 8tone llto13 6tone f 7 toto 16,5 to 14,5
8to 10 13
0,75 1414
n-1,5 e
8tone StOne f 9,5 ton e to :2 s 8tone f 9t0ne 12 to 14 7t0ne f 9,5 fto 16,5
8t022
13,5 13,5Recom- ‘3
13 ‘4 t:;c’s ‘4 t;:e’s to 14,5 to 14,512 to 12,5 12 to 12,5 13 13 12to13 12to13 9,5 9,5 13 13
formersded
for for for for for for for for for forB< 0,67 B ;:,75 p< 0,75 p< 0,75 ~ :;,67 ~:; 75 /3< 0,75 /3< 0,75 /3< 0,54 /3<0,75 /?< 0,75 p< 0,75 /?< 0.46 /9< 0,75 P< 0,67 P G 0!75
IOTE Thestraightlengthsgivenin the table arethe permittedlengthsbetweenthe downstreamendof a W-tubebundleflow straightener(1998)(aadescribedin 12.5.3) and the OWCSplategiventhata particularKingia inataliedupstreamof the W-tubebundleflowstrafghtaner(1996)at a diatenceLf fromthe c+fficaplate.The distanceLf from the oririceplateis measuredto the downstreamerxl of the curvadporthn of the nearaafMonly)bendor of the tee or the downstreamendof thecurvedor wnical Porfiomof the reduceror expander.The recommendedvaluesgivetubebundlelocationsthat areapplicableovera specifiedrangeof p.
Sis theseparationbetweenthe two bendsmeasumdfromthedownstreamendof the curvedportionof the upsbeambandto the upstreamendof thecuwed portionof fhedownstreamband.
Bendsshwld havea radiusof curvatureequalto 1,5D.
ColumnA fcweachfiting giveslengthsccmaapondingto “zeroadd~onalu~*inV vaIues(see 12.5.2).
CotumnB for cashfittinggivesiengthscorrespondingto “0,5% addtionai unsertaiw values(see 12.5.3).
II Isthenumbafof diameterssushthat the upstreamendof the 19-tuIMbundleflow straightener(1998)is situated1D from the downstreamendof tha wrved or mnkai porfionof the nearest fitting.It is deaireMethatrelengthbetweentheupstreamendof the 19-tubebundleflowstmightaner(1998)and the dowrwtfaamendof thecuwedor canicelportionof the near6stfittingahwid be at least2,5D,exceptwhereW vmuldnotgiveanIX3ptStiSVehe fOrthe distance@tWeantheorifice@ateandthe dovmstreamendof the 19-tubebumfieflowsfreiihtener (1998),
if is not poaeiblato find an acceptablelocationfor a 194ubsbundle flowstieightener(1998)downstreamof the particularsittingfor all valueaofLf to whii the mlumn applies.
If p= 0,46a valueof 9,5 is ~sibla.
lf~= 0,54a valuedf 13k possibla.
IS 15675:2006
b) the downstream straight length is shorterthan the 0.5 percent additional uncertaintyvalue specified in columns B.of Table 6; or
c) both the straight length between orifice plateand 19-tube bundle flow straightener (1998)is not in accordance with the valuecorresponding to zero additional uncertaintyshown in columns A of Table 7 and thedownstream straight length is shorterthanthe ‘zero additional uncertainty’ valuespecified in columns A of Table 6.
12.5.5 The values given in Table 7 have beendetermined experimentally with a very long straightlength mounted upstream of the fitting in questionso that the flow immediately upstream of the fittingwas considered as fully developed and swirl-free.Since in practice such conditions are difficult toachieve, there shall be al least 15D of straight pipebetween the fitting listed in Table 7 and the nearestfitting beyond that one, unless the columns relatingto any fitting are used (see example).
Example:
If it is necessary to install a single bend upstreamof an orifice plate of diameter ratio 0.6, there aretwo options using a 19-tube bundle flowstraightener (1998) which will reduce the upstreamlength in comparison with the 42D required (seeTable 6) if no flow conditioner is used. Either aninstallation as in 12.4 is permissible [see Fig. 9 (a)]which has the advantage that any fitting can be
placed at any distance upstream of the single bendor an installation as in Table 7 is permissible [seeFig. 11 (b)] which gives a shorter straight length
$+=%a) Installation Using (12.4)
.
required downstream of the bend but a straightlength required upstream of the bend. If theupstream straight length from the orifice plate tothe bend is greater than or equal to 30D, Table 7can also be used to provide wider range of tubebundle locations but since these locations willrarely be required in designing installations theseoptions are not shown in Fig. 11.
12.6 Zanker Flow Conditioner Plate
12.6.1 Description
The Zanker flow conditioner plate described hereis a development of the Zanker conditioner. TheZanker flow conditioner plate has the samedistribution of holes in a plate but does not havethe egg-box honeycomb attached to the plate;instead the plate thickness has been increased toD/8. It is not patented.
The Zanker flow conditioner plate shown in Fig. 12met the compliance test requirements. A Zankerflow conditioner plate which meets themanufacturing and installations as per thisstandard.
12.6.2 Design
The Zanker flow conditioner plate is illustrated inFig. 12 and consists of 32 bored holes arrangedin a symmetrical circular pattern. The dimensionsof the holes are a function of the pipe insidediameter D and shall be as follows:
a) a ring of 4 central holes of diameter0.141D * 0.00ID on a pitch circlediameter of 0.250 * 0.0025~
KEY
1 — position of any fitting placed at any distanceupstream of the single bend
2 — position of previous fitting placed beforestraight length upstream of the single bend
T===Fb) Installation Using (Table 7)
FIG. 11 EXAMPLE OF INSTALLATIONS WITH A 19-TUBE BUNDLE FLOW STRAIGHTENER (1 998)
DOWNSTREAM OF A SINGLE BEND
22
IS 15675:2006
A1, /\ —
D/8
FIG. 12 DRAWING OF THE ZANKER FLOW CONDITIONER PLATE
b) a ring of 8 holes of diameter 0.1390* 0.001 D on a pitch circle diameter of0.56D * 0.005 6a
c) a ring of 4 holes of diameter 0.136 5D* 0.001 D on a pitch circle diameter of0.75/3 * 0.0075a
d) a ring of 8 holes of diameter 0.1 10D* 0.001 D on a pitch circle diameter of0.85D * 0.008 5f2 and
e) a ring of 8 holes of diameter 0.077D* 0.001 D on a pitch circle diameter of0.90D * 0.009D.
The tolerance on the diameter of each hole is:*0.1 mm for D< 100 mm.
The perforated plate thickness, ?; is such thatOJ.2DstCs0.15D.The flange thkkness dependson the application; the outer diameter and flangeface surfaces depend on the flange type andapplication.
The pressure loss coefficient, K, for the Zankerflow conditioner plate is approximately equal to 3,where K is given by the following equation:
. .+PV2
where
APC = pressure loss across the Zanker flowconditioner plate;
P = density of the fluid in the pipe; and
v = mean axial velocity of the fluid in thepipe.
12.6.3 Installation
L~,the distance between the orifice plate and thenearest upstream fitting, shall beat least equal to17D. The Zanker flow conditioner pIate shall beinstalled so that L~, the distance between thedownstream face of the conditioner plate and theorifice plate, is such that:
7.5Ds L, s L, – 8.5D
The Zanker flow conditioner plate can be usedfor ~ S 0.67.
The distance to a bend (or bend combination) ora tee is measured to the downstream end of thecurved portion of the nearest (or only) bend or ofthe tee. The distance to a reducer or expander ismeasured to the downstream end of the curvedor conical portion of the reducer or the expander.
The locations in this subclause are acceptabledownstream of any fitting. A wider range oflocations for the Zanker flow conditioner plate ispermissible if the range of upstream fittings isrestricted or the overall length between theupstream fitting and the orifice plate is rncreasedor the diameter ratio of the orifice plate is reduced.These locations are not described here.
12.7 Circularity and Cylindricality of the Pipe
12.7.1 The 2D length of the upstream pipe sectionadjacent to the orifice plate (or to the carrier ring ifthere is one) shall be manufactured with specialcare and shall meet the requirement that nodiameter in any plane in this length shall differ by
23
IS 15675:2006
more than 0.3 percent from the mean value of Dobtained from the measurements. The value forthe pipe diameter D shall be the mean of theinternal diameters over a length of 0.5D upstreamof the upstream pressure tapping. The internalmean diameter shall be the arithmetic mean ofmeasurements of at least twelve diameters,namely, four diameters positioned at approximatelyequal angles, to each other, distributed in each ofat least th~e cross-sections evenly distributed overa length of 0.5D, two of the sections being atdistance OD and 0.5D from the upstream tappingand one being in ‘the plane of the weld in the caseof a weld-neck construction. If there is a carrier ring(see Fig. 6), this value of 0:5Dshall be tTWaSUFed
from the upstream edge .of the carrier ring.
Beyond 2D from the orifice plate, the upstreampipe run between the orifice plate and the firstupstream fitting or disturbance may be made upof one or more sections of pipe.
12.7.2 Between 2Dand 10Dfrom the orifice plate,no additional uncertainty in the dischargecoefficient is involved provided that the diameterstep (the difference between the diameters)between any two sections does not exceed0.3 percent of the mean value of D obtained fromthe measurements. Moreover, the actual stepcaused by misalignment and/or change in diametershall not exceed 0.3 percent of D at any point ofthe internal circumference of the-pipe. Therefore,mating flanges would require the bores to bematched and the flanges aligned on installation.Dowels or self-centring gaskets may be used.
12.7.3 Beyond 10D from the orifice plate, rmadditional uncertainty in the discharge coefficientis involved provided that the diameter step (thedifference between the diameters) between any twosections does not exceed 2 percent of the meanvalue of D obtained from the measurements.Moreover, the actual step caused by misalignmentand/or change in diameter shall not exceed.2 percent of D at any point of the internalcircumference of the pipe. If-the pipe diameterupstream of the step is greater than that downstreamof it, the permitted diameter and actual steps areincreased from 2 percent to 6 percent of D. On eachside of the step, the pipe shall have a diameterbetween 0.98 D.and 1.06D. Beyond 10D from theorifice plate, the use of gaskets between sectionswill not violate this requirement provided that in usethey are no thicker than 3.2 mm and they do notprotrude into the flow.
12.7.4At a location which is both beyond 10Dfromthe orifice plate and beyond the first location where
an expander could be fitted in accordance withColumn 10A of Table 6, no additional uncertaintyin the discharge coefficient is involved providedthat the diameter step (the difference between thediameters) between any two sections does notexceed 6 percent of the mean value of D obtainedfrom the measurements specified in 6.4.2.Moreover, the actual step caused by misalignmentand/or than-ge in diameter shall not exce,ed6 percent of D at any point of the intwnalcircumference of the pipe. On each side of the step,the pipe shall have a diameter between 0.94Dand 1.06D. The first location where an expandercould be fitted in accordance with Column 10A ofTable 6 depends on the diameter ratio of the orificeplate, for example, it is 26D from the orifice plateif ~ = 0.6.
12.7.5 An additional uncertainty of 0.2 percentshall be added arithmetically to the uncertainty forthe discharge coefficient if the diameter step (MJ)between any two sections exceeds the limits givenin 12.7but complies with the following relationship:
AD
[)
; + 0.4— <0.002D 0.1 + 2.3/34
and
:<0.05
where
s is the distance of the step from the upstreampressure tapping or, if a carrier ring is used, fromthe upstream edge of the recess formed by thecarrier ring.
If a step is greater than any one of the limits givenin the inequalities above or if there is more thanone step outside the limits in the specified clause,the installation is not in accordance with thisstandard.
No diameter of the dowrrstream straight length,considered along a length of at least 2D from theupstream face of the orifice plate, shall differ fromthe mean diameterof the upstream straight lengthby more than 3 percent. This can be judged bychecking a single diameter of the downstreamstraight length. Mating flanges would require thebores to be matched and the flanges aligned oninstallation. Dowels or self -centring gaskets couldbe used.
12.8 Location of Orifice Plate and CarrierRings
12.8.1 The orifice plate shall be placed in the pipe
24
IS 15675:2006
in such a way that the fluid flows from the upstreamface towards the downstream face.
12.8.2 The orifice plate shall be perpendicular tothe centreline of the pipe to within 10.
12.8.3 The orifice plate shall be centred in the pipe.The distance between the centreline of the orificeand the centrelines of the pipe on the upstreaman-d downstream sides shall be measured, and foreach pressure tapping the components of thedistance between the centreline of the orifice andthe centreline of the pipe in which it is located inthe directions parallel to and perpendicular to theaxis of the pressure tapping shall be determined.
The component in the direction parallel to thepressure tapping eCl, shall for each pressuretapping be such that
e ~ 0.0025D
d 0.1 +2.3~4
e,n, the component in the direction perpendicularto the pressure tapping, shall for each pressuretapping be such Ihat
e ~ 0.005D
m 0.1+ 2.3~4
Ifj for one or more pressure tappings,
0.002 5D 0.005D< ecl ~
0.1 + 2.3~4 0.1 + 2.3/34
An additional uncertainty of 0.3 percent shall beadded arithmetically to the uncertainty on thedischarge coefficient C. The additional uncertaintyshall only be added once even if the aboveinequality holds for several pressure tappings.
In the case where, for any pressure tapping,
0.005D
‘ither ‘CI ‘r ‘cn >0.1 + 2.3/?4
This standard gives no information for forecastingany additional uncertainty due to lack ofconcentricity.
When carrier rings are used, they shall be centred
such that they do not protrude into the pipe at anypoint.
12.9 Method of Fixing and Gaskets
The method of fixing and tightening shall be suchthat once the orifice plate has been installed inthe proper position, it remains so.
It is necessary, when holding the orifice platebetween flanges, to allow for its free thermalexpansion and to avoid buckling and distortion.
Gaskets or sealing rings shall be made andinserted in such away that they do not protrude atany point inside the pipe or across the pressuretappings or slots when corner tappings are used.They shall be as thin as possible, with dueconsideration taken in maintaining the relationshipas defined in 9.
If gaskets are used between the orifice plate andthe annular chamber rings, they shall nat protrudeinside the annular chamber.
13 MARKING
13.1 The meter shall be marked with at least thefollowing information:
a) Manufacturer’s name or trade-mark;
b) Serial number;
c) Maximum flow rate, q~aXin actual volumeunits;
d) Maximum allowable operating pressure;and
e) Minimum flow rate, q~~Xat 1.2 kg/m3 fluiddensity.
13.2 BIS Certification Marking
The product may also be marked with the StandardMark.
13.2.1 The use of the Standard Mark is governedby the provisions of the Bureau of/ndian StandardsAct, 1986 and the Rules and Regulations madethereunder. The details of conditions under whichthe Iicence for the use of the Standard Mark maybe granted to manufacturers or producers maybeobtained from the Bureau of Indian Standards.
25
IS 15675:2006
ANNEX A
(Foreword)
A-1 TABLES OF Discharge COEFFICIENTS AND EXPANSIBILITY @XPANSION) FACTORS(see TABLES 8T0 19)
Table 8 Orifice Plate with Corner Tappings — Discharge Coefficient, C,for D271.12 mm
iam-lter Discharge coemcient, C, for ReDeqUal toatio
P 5X103 1X1O’ 2 x 10’ 3 x 10’ 5X104 7% 10’ 1 x 105 3 x 105 1 X IOG Ixlor” 1 x 108 m
1,10 0,6006 0,5990 0,5980 (),597 6 0,5972 0,5970 0,5969 0,5966 (),596 5 Q,5964 0,5964 ~,5964
1,12 0,6014 0,5985 0,5883 0,5979 0,5975 0,5973 0,5971 0,5968 0,5966 0,5965 0,5965 0,5965
),14 0,6021 0,6000 0,5967 0,5982 0,5977 0,5975 0,5973 0,5969 0,5968 0,5966 0,5966 0,5966
),16 0,6020 O,wt 5 0,5991 0,5985 0;598 O 0,5976 0,5976 0,5971 0,5969 0,5968 o,59fj 8 0,5968
),18 0,6036 0,6011 0,5995 0,5989 0,5983 0,5981 0,5978 0,5974 0,5971 0,5970 (),597 () IJ,5969
),20 0,6045 0,6017 0,6000 0,5993 0.5987 0,5984 0,5961 0,5976 0,5974 0,5972 (),597 2 (),597 1
),22 0,6053 0,6023 0,6005 0,5998 0,5991 0,5987 0,5985 (),597 9 0,5976 0,5974 (),597 4 0,5974
),24 0,6062 0,6030 0,6010 0,6002 0,5995 0,5991 0,5968 0,5982 0,5979 0,5977 (3,597 6 (),5976
),26 0,6072 0,6038 0,6C1 6 0,6007 0,5999 0,5996 0,5992 0,5986 0,5982 0,5980 0,5979 (),597 9
),26 0,6083 0,6046 0,6022 0,6013 0,6004 0,6000 0,5997 0,599 Q 0,5986 0,5983 0,5982 0,5981
),30 0,6095 0,6054 0,6029 0,6019 0,6010 0,6005 0,6001 0,599.4 0,5989 0,5986 0,59135. 0,5984
1,32 0,6107 0,6063 0,6036 0,6026 0,6016 0,6011 0,6006 0,5996 0,5993 0,5990 1),598 8 0,5967
),34 0,6120 0,6073 0,6044 0,6033 0,6022 0,6017 0,6012 0,6003 0,5998 0,5993 13,5992 0,599 I
),36 0,6135 0,6084 0,6053 0,8040 0,6029 0,6023 0,6018 0,6008 0,6002 0,5997 1),5996 0,5994
),38 0,6151 0,6096 0,6062 0,6049 0,6036 0,6030 0,6024 0,6013 0,6007 0,6001 (),599 9 (),599 8
),40 0,6168 0,6109 0,6072 0,6058 0,6044 0,6037 0,6031 0,6019 0,61)f 2 (),600 6 0,6003 Q 60() 1
),42 0,6167 0,6122- 0,6083 0,6067 0,6052 0,6044 0,6038 0,6025 0,6017 0,6010 0,6007 0,6005
),44 0,6207 0,6137 0,6094 0,6077 0,6061 0,6052 0,6045 0,6031 0,6022 0,6014 0,6011 O,fjfjo 8
),46 0,6228 0,6152 0,6106 0,6067 0,6070 086061 0,6053 0,6037 0,6027 (1,601 9 0,6015 13,6fjl 2
1,48 0,6251 0,6169 0,6116 0,6098 0,6079 0,6069 0,6061 0,6043 0,6033 0,6023 0,61)1 9 0,6015
),50 0,6276 0,6186 0,6131 0,6109 0,6088 0,6078 0,6069 0,6050 0,6038 0,6027 0,6022 I),6(jl 8
),51 0,6289 0,6195 0,6138 0,6115 0,6093 0,6082 0,6073 0,6053 0,6040 0,6Q29 fJ,6024 0,6&I 9
1,52 0,6302 0,6204 0,6144 0,6121 0,6098 0,6087 0,6077 0,6056 0,6043 0,6030 iJ,6Q25 (),602 ()
),53 0,6316 0,6213 0,6151 0,6126 0,6103 0,6091 0,6080 0,6059 (),6()4 5 0,6032 (),602 6 0,6021
1,54 0,6330 0,6223 0,6158 0,6132 0,6106 0,6095 0,6084 0,6061 0,6047 0,6033 0,6027 fJ,602 1
),55 0,6344 0,6232 0,6165 0,6138 0,6112 0,6099 0,6088 0,6064 1),61)49 0,6(334 ();6028 0,6022
1,56 — 0,6242 0,6172 0,6143 0,6117 0,6103 0,6091 0,6066 0,6050 0,6035 0,6028 0,6022
3,57 — 0,6252 0,6179 0,6149 0,6121 0,6107 0,6095 0,6069 0,6052 0,6t)36 (),602 8 0,6022
3,58 — 0,6262 0,6185 0,6155 0,6126 0,6111 0,6096 -0,6070 0,6053 0,6036 0,6028 0,6021
3,59 — 0,6272 0,6192 0,6160 0,6130 0,6114 0,6101 0,6072 0,6054 0,6036 0,6026 (),602 0
D,60 — 0,6262 0,6198 0,6165 0,6T34 0,6117 0,6103 0,6073 0,6054 0,6035 0,6027 0,6019
3,61 — 0,6292 0,6205 0,6170 0,6137 0,6120 0,6106 0,6074 0,6054 0,6034 0,6025 0,6017
D,62 — 0,6302 0,6211 0,6175 0,6140 0,6123 0,6108 0,6075 0,6054 0,6033 0,6023 0,6014
D,63 — 0,6312 0,6217 0,6179 0,6143 0,6125 0,6109 0,6075 0,6052 0,6030 0,6021 (),6Q1 1
D,64 — 0,6321 0,6222 0,6163 0,6145 0,6126 0,6110 0,6074 0,6051 0,6028 t3,601 7 0,6007
D,65 — 0,6331 0,6227 0,6166 0,6147 0,6127 0,6110 0,6073 0,6048 0,6024 0,6013 i3,6LXj2
0,66 — 0,6340 0,6232 0,6189 0,6148 0,6128 0,6110 0,6071 0;6045 0,6020 0,6008 0,5997
0,67 — 0,6348 0,6236 0,6191 0,6149 0,6127 0,6108 0,6066 0,6041 0,6014 0,6002 (),599 (?
0,68 — 0,6357 0,6239 0,6193 0,6149 0,6126 0,6106 0,6064 0,6036 0,6006 (),599 5 0,5983
0,69 — 0,6364 0,6242 0,6193 0,6147 0,6124 0,6104 0,6059 0,6030 0,6001 0,5987 0,5974
0,70 — 0,6372 0,624-4 0,6193 0,6145 0,6121 0,6100 0,6053 0,60(?3 0,5992 (),597 8 0,5964
0,71 — 0,6378 0,6245 0,6192 0,6142 0,6117 0,6094 0,6046 0,6014 0,5982 0,5967 0,595 ~
0,72 — 0,6363 0,6244 0,6189 0,6138 0,6111 0,6086 0,6038 0,6005 0,5971 (),595 5 0,594 c
0,73 — 0,6388 0,6243 0,6186 0,6132 0,6f04 0,6080 0,6028 0,5993 0,5958 (),594 2 0,592.f
0,74 — 0,6391 0,6240 0,6181 0,6125 0,6096 0;6071 0,6016 0,5960 0,5943 0,5926 0,591 c
0,75 — 0,6394 0,6236 0,6174 0,6116 0,6086 0,6060 0,6003 0,5965 0,5927 (),5909 0,589 ~
NOTE Thistable ia givenfor cmnvanienoe.The valueegivenare not intendedfor pmcleainterpolatkm.Extmpoiationianot permitted.
26
-—.-. —. ..._. G____ —— . . . . . . .
IS 15675:2006
Table 9 Orifice Plate with D and D/2 Tappings — Discharge Coefficient, C,for D271.12mm
am-ter Discharge coefficient, C, for ReD equal toItio
P 5 XI03 1 x T04 2 x 104 3 x 104 5XI04 7 x 104 1 x 105 3X105 1 x 106 1 x 107 1 x 106 m
,10 0,6003 0,5967 0,5977 0,5973 0,5969 0,5967 0,5966 0,5963 0,5962 0,5961 0,5961 0,5960
,12 0,6010 0,5991 0,5979 0,5975 0,5971 0,5969 0,5967 0,5964 0,5962 0,5961 0,5961 0,5961
,14 0,6016 0,5995 0,5982 0,5977 0,5972 0,5970 0,5968 0,5965 0,5963 0,5962 0,5961 0,5961
,16 0,6023 0,6000 0,5985 0,5980 0,5974 0,5972 0,5970 0,5966 0,5964 0,5962 0,5962 0,5962
,+8 0,6029 0,6004 0,5989 0,5982 0,5977 0,5974 0,5971 0,5967 0,5965 0,5963 0,5963 0,5963
,20 0,6037 0,6009 0,5992 0,5985 0,5979 0,5976 0,5974 0,5969 0,5966 0,5984 0,5964 0,5964
,22 0,6044 0,6015 0;5996 0,5989 0,5982 0,5979 0,5976 0,5971 0,5968 0,5966 0,5965 0,5965
,24 0,6053 0,6021 0,6001 0,5993 0,5985 0,5982 0,5979 0,5973 0,5970 0,5967 0,5967 (),596 6
,26 0,6062 0,6027 0,6006 0,5997 .0,5989 0,598.5 0,5982 0,5975 0,5972 0,5969 0,5969 0,5968
,26 0,6072 0,6034 0,6011 0,6002 0,5993 0,5989 .0,5985 0,5978 0,5975 0,5972 0,5971 0,5970
,30 0,6082 0,6042 0,6017 0,6007 0,5998 0,5993 0,5989 0,5982 0,5978 0,5974 0,5973 0,5973
,,32 0,6094 0,6051 0,6024 0,6013 0,6003 0,5998 0,5994 0,5986 0,5981 0,5977 0,5976 0,5975
1,34 0,8107 0,6060 0,6031 0,6020 0,6009 0,6004 0,5999 0,5990 0,5965 0,5981 0,5979 03978
1,36 “0,612 1 0,6071 0,6040 0,6027 0,6016 0,6010 0,6005 0,599”5 0,5989 0,5964 0,5963 0,5981
1,36 0,6137 0,6082 0,6049 0,6035 0,6023 0,6016 0,6011 0,6000 0,5994 0,5986 0,5966 0,5985
1,40 0,6153 0,6095 0,6059 0,6044 0,6031 0,6024 0,6018 0,6006 0,5999 0,5993 0,5991 0,5989
1,42 0,6172 0,6109 0,6070 0,6054 0,6039 0,6032 0,6025 0,6012 0,6005 0,5996 0,5995 0,5993
),44 0,6192 0,6124 0,6082 0,6065 0,6049 0,6041 0,6034 0,6019 0,6011 0,6003 0,6000 0,5997
},46 0,6214 0,6140 0,6094 0,6076 0,6059 0,6050 0,6042 0,6027 0,6017 0,6008 0,6005 0,6002
),48 0,6238 0,6157 0,6108 0,6088 0,6070 0,6060 0,6052 0,6035 0,6024 0,6014 0,6010 0,6006
),50 0,6264 0,6176 0,6123 0,6101 0,6081 0,6071 0,6062 0,6043 0,6031 0,6020 0,8016 0,6011
),51 0,6278 0,6186 0,6131 0,6108 0,6087 0,6076 0,6067 0,6047 0,6035 0,6023 0,6019 0,61314
),52 0,6292 0,6197 0,6139 0,6115 0,6093 0,6082 0,8072 0,6052 0,6039 0,6027 0,6021 0,6016
),53 0,6307 0,6207 0,6147 0,6123 0,6100 0,6068 0,6076 0,6056 0,6043 0,6030 0,6024 0,6019
),54 0,6322 0,6218 0,6155 0,6130 0,6106 0,6094 0,6063 0,6061 0,6047 0,6033 0,6027 0,6021
),55 0,6337 0,6229 0,6164 0,6138 0,6113 0,6100 0,6069 0,6065 0,6050 0,6036 0,6030 0,6024
1,56 — 0,8241 0,6!73 0,6145 0,6119 0,6106 0,6095 0,6070 0,6054 0,6039 0,6032 0,6026
1,57 — 0,6253 0,6182 0,6153 0,6126 0,6112 0,6100 0,6075 0,6058 0,6042 0,6035 0,6028
),58 — 0,6265 0,6191 0,6161 0,6133 0,6119 0,6106 0,6079 0,606”2 0,6045 0,6036 0,61330
1,59 — 0,6277 0,6200 0,6169 0,6140 0,6125 0,6112 0,6084 0,6066 0,6048 0,6040 0,6032
1,60 — 0,6290 0,6210 0,6177 0,6147 0,6131 0,6118 0,6066 0,6070 0,6051 0,804.2 0,6034
3,61 — 0,6303 0,6219 0,6186 0,6154 0,6138 0,6124 0,6093 0,6073 0,6053 0,6044 0,6036
EI,62— 0,6316 0,6229 0,6194 0,6161 0,6144 0,6129 0,6097 0,6077 0,6056 0,6046 0,6037
D,63— 0,632 9 0,6238 0,6202 0,6168 0,6150 0,6135 0,6102 0,6080 0,6058 0;6048 0,6039
0,64 — 0,634 3 0,624 8 0,6210 0,6175 0,6156 0,6140 0,6106 0,6083 0,6060 0,6050 0,6039
0,65— o,635 6 oi625 8 0,621 9 0,618 ‘2 0,6162 0,6146 0,6109 0,6086 0,6062 0,6051 0,6040
0;66 — 0,637 0 0,626 8 0,622 7 0,616 6 0,616 6 0,6151 0,6113 0,6066 0,6063 0,6051 0,6040
0,67— 0,638 4 0,627 7 0,623 5 0,619 5 0,617 4 0,615 6 0,6116 0,6090 0,6064 0,6052 0,6040
0,68— 0,639 8 0,628 7 0,624 3 0,620 1 0,617 9 0,6161 0;612 O 0,6092 0,6065 0,6052 0,6039
0,69— 0,641 1 0,629 6 0,625 0 0,620 7 0,618 5 0,616 5 0,612 2 0,6094 0,6065 0,6051 0,6038
0,7o— 0,642 5 0,630 5 0,625 8 0,621 3 0,618 9 0,616 9 0,612 5 0,609 5 0,606 5 0,6051 0,6037
0,7 l— 0,643 9 0,631 5 0,626 5 0,621 8 0,619 4 0,617 3 0,612 7 0,609 6 0,606 4 0,604 9 0,6035
0,72— 0,645 3 0,632 3 0,627 2 0,622 3 0,619 8 0,617 6 0,612 8 0,608 6 0,606 3 0,604 7 0,6032
0,73— 0,646 7 0,633 2 0,627 9 0,622 8 0,620 2 0,617 9 0,612 9 0,609 6 0,606 1 0,604 5 0,6029
0,74— 0,646 0 0,634 0 0,628 5 0,623 3 0,620 6 0,618 2 0,613 0 0,609 5 0,605 9 0,604 2 0,6025
0,75— 0,649 4 0,634 9 0,629 1 0,623 7 0,620 9 0,618 4 0,613 0 0,609 4 0,605 6 0,603 8 0,6021
NOTE Thistsblaisgivenformnvenience.Thevslues givenara not intendedfor preciseinterpolation.Extrapolationis not perrnittad.
27
IS 15675:2006
Table 10 Orifice Plate with Flange Tappings — Discharge Coefficient, C,for D= 50 mm
Iiam.eter Discharge coefficient, C, for Ren equai toratio
B 5X109 1 x 104 2X104 3 x 104 5 x ‘lo4 7 x 104 1 x 105 3X105 1 x 106 1 x 107 i x 108 m
0,25 0,6102 0,6069 0,6046 0,6040 0,6032 0,6029 0,6025 0,6019 0,60$6 0,61)14 I),60f 3 0,6012
0,26 0,6106 0,6071 0,6050 0,6041 0,6033 0,6029 0,6026 0,6020 0,6t)l 6 0,6014 (),601 3 (3,601 2
0,26 0,6114 0,6076 0,6053 0,6044 0,6035 0,6031 0,6028 0,6021 0,6017 f3,601 4 0,6013 0,6012
0,30 0,6123 o,fXlf32 0,6057 0,6047 0,6038 0,6034 0,6030 0,6022 0,6016 0,6015 0,60j 4 (),61)13
0,32 0,6132 0,6089 0,6062 0,6052 0,6042 0,6037 0,6032 ti,6024 0,6019 0,6016 0,6014 (),601 3
0,34 0,6143 0,6097 0,6068 0,6056 0,6045 0,6040 0,6Q35 0,6Q26 0,602 I (),601 7 0,6016 13,60f 4
0,36 0,6155 0,6105 0,6074 0,6062 0,6050 0,6044 0,6039 0,6029 0,6023 0,6019 0,6017 i),601 6
0,38 0,6169 0,6115 0,6061 0,6068 0,6055 0,6049. 0,6043 0,6032 0,6026 0,6021 0,6019 0,6017
0,40 0,6184 016125 0,6089 0,6075 0,6061 0,6054 0,6048 0,6036 0,6029 (),6()2 3 0,6021 0,6019
0,42 0,6200 0,6137 0,6098 0,6082 0,6068 0,6060 0,6054 0,6041 0,6033 0,6026 0,6023 0,6021
0,44 0,6219 0,6150 0,6108 0,6091 0,6075 0,6067 0,6060 0,6045 0,6037 lj,61)29 0,6026 (),602 3
G,46 0,6239 0,6164 0,6119 0,6100 0,6083 0,6074 0,6067 0,6051 0,6041 0,8033 0,6029 0,6026
0,48 0,6260 0,6180 0,6130 “0,6110 0,6092 0,6082 0,6074 0,6057 0,6046 0,6036 (),603 2 I),61J28
0,50 0,6284 0,6196 0,6143 0,6121 0,6101 0,6091 0,6062 0,6063 0,6051 0,604 () 0,6036 i3,603 1
0,51 0,6297 0,6205 0,6149 0,6127 0,6106 0,6095 0,6066 0,6066 0,6054 0,6Q42 0,6037 (),603 3
0,52 0,6310 0,6214 0,6156 0,6133 0,6111 0,6100 0,6090 0,6069 .0,6056 0,6044 (),603 9 (),603 4
0,53 0,6324 0,6224 0,6163 0,6139 0,6116 0,6105 0,6094 0,6073 0,6059 i),6(146 D,6Q4 1 13,6035
0,54 0,6338 0,6234 0,6171 0,6145 0,6122 0,6109 0,6099 0,6076 0,6062 0,6046 (),604 2 0,6037
0,55 0,6352 0,6244 0,6178 0,6152 0,6127 0,6114 0,6103 0,6060 0,6065 0,6050 (),604 4 0,6038
0,56 0,6367 0;6254 0,6186 0,6159 0,6133 0,6119 0,6108 0,6083 0,6067 0,6052 13,6Q45 (J,61)39
0,57 0,6383 0,6265 0,6194 0,6165 0,6138 0,6124 0,6112 (),6()8 7 0,6070 0,6054 o;6Q47 0,6040
0,58 0,6399 0,6276 0,6202 0,6172 0,6144 0,6130 0;611 7 0,6090 0,6073 0,6056 13,6Q48 0,6041
0,59 0,6416 0,6287 0,6210 0,6179 0,6150 0,6135 0,6122 0,6093 0,6075 0,6058 13,6Q5() 0,6042
0,60 0,6433 0,6299 0,6218 0,6186 0,6155 0,6’140 0,6126 0,6097 0,6078 0,6059 (),605 1 (),604 3
0,61 0,6450 0,6310 0,6227 0,6193 0,6161 0,6145 0;613 1 0,6100 0,6080 0,6060 0,6051 o,6Q43
0,62 0,646~ 0,6322 0,6235 0,6200 0,6167 0,6150 0,6135 0,6103 (),608 2 (),606 2 0,6052 0,6043
0,63 0,6486 0,6334 0,6243 0,6207 0,6173 0,6155 0,6139 0,6106 0,6084 13,eiofj2 0,6053 o,6Q43
0,64 0,6505 0,6347 0,6252 0,6214 0,6178 0,6160 0,6144 0,6109 0,6086 0,6063 0,6053 0,6043
0,65 0,6524 0,6359 0,6260 0,6221 0,6184 0,6164 0,6148 0,6111 0,6068 (),606 4 0,6053 0,6042
0,66 0,6544 0,6371 0,6269 0,6226 0,6189 0,6169 0,6152 0,6114 0,6089 0,6064 0,6Q5.2 0,6041
0,67 0,6564 0,6384 0,6277 0,6234 0,6194 0,6173 0,6155 0,6116 0,6090 0,6063 0,605 I o,603 ~
0,68 0,6584 0,6396 0,6285 0s241 0,6199 0,6177 0,6156 0,6117 0,6090 o,60fj 2 (),605 o 0,603 ]
0,69 0,6604 0,6409 0,6293 0,6247 0,6204 0,6181 0,6161 0,6119 0,6090 o,6Q6 1 o,6Q48 o,603 ~
0,70 0,6625 0,6421 0,6301 0,6253 0,6208 0,6165 0,6164 0,6120 0,6090 0,6060 o,6Q45 o,603 ~
0,71 0,6646 0,6434 0,6309 0,6259 0,6212 0,6188 0,6166 0,6120 0,6089 0,6057 o,6Q43 o,602 t
0,72 0,6667 0,6446 0,6316 0,6265 0,6216 0,6190 0,6168 0,6120 0,6086 0,6055 0,6039 0,6024
0,73 0,6689 0,6459 0,6323 0,6270 0,6219 0,6193 0,6170 0,6120 0,6086 0,6051 o,6Q35 o,601 ~
0,74 0,6710 0,6471 0,6330 0,6275 0,6222 0,6195 0,6171 0,6119 (),6()8 4 o,6Q47 0,6030 o,60f 4
0,75 0,6732 0,6463 ‘0,633 7 0,6279 0,6224 0,6196 0,6171 0;611 ? 0,608 f (),604 3 0,6025 0,600 [.. -—- —NOTE This.lable is givenfor convenience.Ttsevaluesgivenam not intendedfor preciseinterpolation.ExtrepolstJonie not permitted.
28
IS 15675:2006
Tablell Orifice Plate with Flange Tappings -Dkcharge Coefficient, C,for D= 75 mm
liam-eter Discharge coefficient, C, for ReD equal to.atio
P 5 x 103 1 x 104 2 x 104 3X164 5 x 104 7 x 104 1 x 105 3X105 1 x 106 1 x 107 1 Xloa m
2,17 0,6027 0,6003 0,5988 0,5982 0,5977 0,5974 0,5972 0,5967 0,5965 0,5964 o,5g64 o,5963
3,18 0,6031 0,6005 0,5990 0,5984 0,5978 0,5975 0,5973 0,5968 0,5966 0,5964 0,5964 0,5964
),20 0,6038 0,6011 0,5994 0,5987 0,5981 0,5977 0,5975 0,5970 0,5967 o,59_66 o,5965 0,5965
1,22 0,6046 0,6016 0,5998 0,5990 0,5984 0,5980 0,5977 0,5972 0,596.9 0,5967 0,5967 0,5966
1,2-4 0,6054 0,6022 0,6002 0,5994 0,5987 0,5983 0,5980 0,5974 0,597 I o,5969 0,5969 0,5968
1,26 0,6064 0,6029 0,6007 0,5999 0,5991 0,5987 0,5984 0,5977 (),597 4 0,5971 (),597 1) 0,597 1)
1,28 0,6074 0,6036 0,6013 0,6004 0,5995 0,5991 0,5987 0,5980 0,5976 (3,5974 0,5973 0,5972
1,30 0,6084 0,6044 0,6019 0,6009 0,6000 0,5995 0,5991 0,5984 0,5979 0,5976 0,5975 0,5974
1,32 0,6096 0,6053 0,6026 0,6015 0,6005 0,6000 0,5996 0,5988 0,5983 0,5979 0,5978 (),597 ~
),34 0,6109 0,6062 0,6033 0,6022 0,6011 0,6006 0,6001 0,5992 0,5987 0,5983 0,598 I 0,5980
),36 0,6123 0,6073 0,6042 0,6029 0,6017 0,6012 0,6007 0,5997 0,5991 0,5986 0,5984 0,5983
3,38 0,6139 0,6084 0,6051 0,6037 0,6025 0,6018 0,6013 0,6002 0,5995 0,599 (3 o,5988 0,5986
1,40 0,6155 0,6097 0,6060 0,6046 0,6032 0,6025 0,6020 0,6008 0,6000 0,5994 0,5992 (3,599 o
>,42 0,6174 0,6110 0,6071 0,6055 0,6041 0,6033 0,6027 0,6014 0,6006 0,5999 0,5996 (3,599 4
2,44 0,6194 0,6125 0,6083 0,6066 0,6050 0,6042 0,6035 0,6020 0,6012 0,6004 0,6001 0,5998
2,46 0,6216 0,6141 0,6095 0,6077 0,6059 0,6051 0,6043 0,6027 0,6018 0,6009 0,6005 0,6002
0,48 0,6239 0,6158 0,6108 0,6089 0,6070 0,6060 0,6052 0,6035 0,6024 0,6014 0,6010 0,6006
D,50 0,6264 0,6176 0,6123 0,6101 0,6081 0,6070 0,6061 0,6042 0,6031 0,6020 0,6015 0,601 I
D,51 0,6278 0,6186 0,6130 0,6107 0,6086 0,6075 0,6066 0,6046 0,6034 0,6022 o,60’f 7 0,6013
D,52 0,6292 0,6196 0,6138 0,6114 0,6092 0,6081 0,6071 0,6050 0,6037 0,6025 0,6020 0,6015
0,53 0,6306 0,6206 0,6145 0,6121 0,6098 0,6086 0,6076 0,605 ~ 0,6041 0,6028 0,6022 0,6017
0,54 0,6321 0;621 6 0,6153 0,6128 0,6104 0,6092 0,6081 0,6058 0,6044 0,6030 0,6024 0,60.19
0,55 0,6336 0,6227 0,6161 0,6135 0,6110 0,6097 0,6086 0,6062 0,6047 0,6033 0,6027 0,6021
0,56 0,6352 0,6238 0,6170 0,6142 0,6116 0,6103 0,6091 0,6066 0,6051 0,6035 0,6029 0,6022
0,57 0,6368 0,6249 0,6178 0,6149 0,6122 0,6108 0,6096 0,6070 0,6054 0,6038 0,603 I o,6024
0,58 0,6385 0,6261 0,6186 0,6156 0,6128 0,6114 0,6101 0,6074 0,6057 0,6040 0,6032 0,6025
0,59 0,6402 0,6273 0,6195 0,6164 0,6134 0,6119 0,6106 0,6078 (),606 o 0,6042 0,6034 0,6026
0,60 0,6419 0,6284 0,6203 0,61.71 0,6140 0,6125 0,6111 0,6082 0,6063 0,6044 0,6035 0,6027
0,61 0,6437 0,6296 0,6212 0,6178 0,6146 0,6130 0,6116 0,6085 0,6065 0,6045 0,8036 0,6028
0,62 0,6455 0,6309 0,6221 0,6186 0,6152 0,6135 0,6120 0,6088 0,6067 0,6047 0,6037 0,6028
0,63 — 0,6321 0,6229 0,6193 0,6158 0,6140 0,6125 0,6091 0,6069 0,6048 0,6038 0,6028
0,64 — 0,6333 0,6238 0,6200 0,6164 0,6145 0,6129 0,6094 0,6071 -0,6048 0,6038 0,6028
0,65 — 0,6346 0.6246 0,6207 0;6169 0,6150 0,6133 0,6097 0,6073 0,6049 0,6038 0,6027
0,66 — 0,6358 0,6255 0,6213 0,6174 0,6154 0,6137 0,8099 0,6074 0,6048 0,6037 0,6026
0,67 — 0,6370 0,6263 0,6220 0,6179 0,6158 0,6140 0,6100 0,6074 0,6048 0,6036 0,6024
0,68 — 0,fJ382 0,6270 0,6226 0,6184 0,6162 0,6143 0,6102 0,6074 0,6046 0,6034 0,6021
0,69 - 0,6395 0,6278 0,6232 0,6188 0,6165 0,6145 0,6102 0,6074 0,6045 0,603 I 0,6018
0,70 — 0,6407 0,6285 0,6237 0,6191 0,6168 0,6147 0,6102 0,6073 0,6042 0,6028 0,6014
0,71 — 0,6418 0,6292 0,6242 0,6194 0,6170 0,6148 0,6102 0,6071 0,6039 0,6024 0,6010
0,72 — 0,6430 0,6298 0,6246 0,6197 0,6171 0,6149 0,6101 0,6068 0,6035 0,6019 0,6004
0,73 — 0,6441 0,6304 0,6250 0,61”99 0,6172 0,6149 0,6099 0,6065 0,6030 0,6014 0,5998
0,74 — 0,6451 0,6310 0,6253 0,6200 0,6173 0,6149 0,6096 0,6061 0,6025 0,6006 0,599.1
0,75 — 0,6462 0,6314 0,6256 0,6201 0,6172 0,6147 0,6093 0,6056 0,6018 0,6000 0,5963
NOTE This table is givenfor mnvsnisnce.The valuesgivenare not intendedfor presiseinterpolation.Extrapolationis not permMed.
29
IS 15675:2006
Table 12 Orifice Plate with Flange Tappings — Discharge Coefficient, C,for D=100mm
iam-]ter Discharge coefficient, C, fOr &?DeqUa[ tOatio
B 5X103 1 x 104 2X104 3X104 5X104 7 x 104 1 XI05 3 x 105 1 x 106 1 x fol 1 x ‘lo~ w
),13 0,6014 0,5994 0,5982 0,5977 0,5973 0,5971 0,5969 0,5966 0,5964 0,5963 0,5962 0,5962
),14 0,6018 0,5997 0,5984 0,5979 0,5974 0,5972 0,5970 0,5986 0,5964 0,5963 0,5963 0,5963
),16 0,6025 0,6001 0,5987 0,5981 0,5976 0,5974 0,5972 0,5968 0,5965 0,5964 0,5964 0,5964
),18 096032 0.6006 0,599 I 0,5985 0,5979 0,5976 0,5974 0,5969 0,5967 0,5965 0,5965 0,5965
),20 0,6039 0,6012 0,5995 0,5988 0,5982 0,5979 0,5976 0,5971 0,5969 0,5967 0,5966 0,5966
),22 0,61M 7 0,6017 0,5999 0,5992 0,5985 0,5981 0,5979 0,5973 0,5970 0,5989 0,5968 0,6988
),24 0,6056 0,6024 0,6004 0,5996 0,5988 0,5985 0,5982 0,5976 0,5973 0,5970 0,5970 0,5969
),26 0,6065 0,6030 0,6009 0,6000 0,5992 0,5988 0,5985 0,597-9 0,5975 0,5973 0,5972 0,5971
),28 0,6075 0,6038 0,6014 0,6005 0,5997 0,5992 0,5989 0,5982 0,5978 0,5975 0,5974 0,5974
),30 0,6086 0,6046 0,6021 0,6011 0,6002 0,5997 0,5993 0,5985 0,5981 0,5978 0,5977 0,5976
),32 0,6098 0,6054 0,6028 0,6017 0,6007 0,6002 0;5998 0,5989 0,5985 0,5981 0,5980 0,5979
3,34 0,6111 0,6064 0,6035 0,6024 .0,6013 0,6007 0,6003 0,5994 0,5988 0~5984 0,5983 0,5982
1,36 0,6125 0,6075 0,6043 0;6031 0,6019 0,6013 0,6008 0,5998 0,5993 0,5988 0,5986 0,5985
3,38 0,6141 0,6086 0,6052 0,6039 0,6026 0,6020 0,6015 0,6004 0,5997 0,5992 0,5990 0,5988
3,40 0,6157 0,6099 0,6062 0,6048 0,6034 0,6027 0,6021 0,6009 0,6002 0,5996 0,5994 o,=
0,42 0,6176 0,6112 0,6073 0,6057 0,6042 0,6035 0,6029 0,6015 0,6008 0,6001 0,5998 0,5996
D,44 0,6196 0,6127 0,6084 0,6067 0,6051 0,6043 0,6036 0,6022 0,6013 0,6005 0,6002 0,8000
0,46 0,6217 0,6142 0,6097 0,6078 0,6061 0,6052 0,6044 0,6029 0,6019 0,6010 0,6007 0,8003
0,48 0,6241 0,6159 0,6110 0,6090 0,6071 0,6061 0,6053 0,6036 0,6025 0,6015 0,6011 0,6007
0,50 0,6266 0,6177 0,6124 0,6102 0,6081 0,6071 0,6062 0,6043 0,6031 0,6020 0,6016 0,6011
0,51 0,6279 0,6187 0,6131 0,6108 0,6087 0,6076 0,6067 0,6047 0,6034 0,6023 0,6018 0,6013
0,52 0,6293 0,6197 0,6138 0,6115 0,6092 0,6081 0,6071 0,6051 0,6038 0,6025 0,6020 0,6015
0,53 0,6307 0,6207 0,6146 0,6121 0,6098 0,6086 0,6076 0,6054 0,6041 0,6028 0,6022 0,6017
0,54 0,6322 0,6217 0,6153 0,6128 0,6104 0,6091 0,6081 0,6058 0,6044 0,6030 0,6024 0,6018
0,55 — 0,6227 0,6161 0,6135 0,6109 0,6097 0,6085 0,63362 0,6047 0,6032 0,6026 0,6020
0,56 — 0,6238 0,6169 0,6141 0,6115 0,6102 0,6090 0,6065 0,6050 0,6034 0,6028 0,6021
0,57 — 0,6249 0,6177 0,6148 0,6121 0,6107 0,6095 0,6069 0,6052 0,6036 0,6029 0,6022
0,58 — 0,6260 0,6185 0,6155 0,6127 0,6112 0,6100 0,6072 0,6055 0,6038 0,6031 0,6023
0,59 — 0,6271 0,6193 0,6162 0,6132 0,6117 0,6104 0,6076 0,6058 0,6040 0,6032 0,6024
0,60 — 0,628.3 0,6201 0,6169 0,6136 0,6122 0,6108 0;6079 0,6060 0,6041 0,6033 0,6025
0,61 — 0,6294 0,6209 0,6176 0,6143 0,6127 0,6113 0,6082 0,6062 0,6042 0,6033 0,6025
0,62 — 0,6306 0,6218 0,6182 0,6149 0,6132 0,6117 0;6085 .0,6064 0,6043 0,6033 0,6024
0,63 — 0,6318 0,6226 0,6189 0,6154 0,6136 0,6120 0,6087 0,6065 0,6043 0,6033 0,6024
0,64 — 0,6329 0,8233 0,6195 0,6159 0,6140 0,6124 0,6089 0,6066 0,6043 0,6033 0,6022
0,6 5— 0,6341 0,6241 0,6201 0,6163 0,6144 0,6127 0,6091 0,6067 0,6042 0,6031 0,6021
0,66 — 0,6353 0,6249 0,6207 0,6168 0,6148 0,6130 0,6092 0,6067 0,6041 0,6030 0,6019
0,67— 0,6364 0,6256 0,6212 0,6172 0,6151 0,6132 0,6092 0,6066 0,6040 0,602’8 0,6016
0,68— 0,6375 0,626 3 0,6218 0,6175 0,6153 0,6134 0,6093 0,606.5 0,6037 0,6025 0,6012
0,69— 0,638 7 0,626 9 0,6222 0,6178 0,6155 0,6135 0,6092 0,6063 0,6034 0,6021 0,6008
0,7o— 0,639 7 0,627 5 0,6226 0,6180 0,6157 0,6136 0,6091 0,6061 0,6031 0,6016 0,6002
0,7 l— 0,840 8 0,628 0 0,6230 0,6182 0,6157 0,6136 0,6089 0,6058 0,6026 0,6011 0,5997
0,72— 0,841 8 0,628 5 0,623 3 0,618 3 0,6157 0,6135 0,608 6 0,605 4 0,6020 0,6005 0,599 c
0,73— 0,642 8 0,629 0 0,623 5 0,618 3 0,615 7 0,6133 0,808 3 0,604 9 0,601 4 0,5998 0,5982
0,74— 0,843 7 0,629 3 0,623 6 0,618 3 0,615 5 0,6131 0,607 8 0,604 3 0,600 6 0,598 9 01597:
0,75— 0,644 5 0,629 6 0,623 7 0,618 1 0,615 3 0,612 7 0,607 2 0,603 6 0,599 8 0,598 0 0,596;
NOTE Thistableisgivenforconvenience.Thevaluesgiven are not intended for precise interpolation. Extrqmlation is not permitted.
*
30
IS 15675:2006
Table13 Orifice Plate with Flange Tappings -Discharge Coefficient, C,for D=150mm
—am.terItio
~
,10
,12
,14
,16
,18
z
,22
,24
,26
,28—,30
1,32
1,34
1,36
1,38
z
),42
),44
),46
l,4e
z
),51
3,52
3,s
),Wj-@
3,5f
1,57
D,5[D,5:
G
0,6’
0,6
0,6
0,6
G
0$(
0,6
0,6
0,6
G
0,7
0,7
0,7
0,7
0,7—
Dischsrge-coefficient, C, fOr~eDeqUal.tO
x 104 x 10s 3 x 105 x 106 x 107 x 108 Ix 103 I x 104
Eiar),599 3
),599 8
),600 2
),600 7
),601 3
),601 9
3,6025
3,6032
D,6039
x 404 1X184 ;XI04 m
=
,5963
,5964
,5965
1,5966
11,5962
1,5863
1,5864
1,5965
1,5966
,6005
,6012
,6016
,6025
,6033
,6041
,6049
,6057
,6067
,6077
,5978
,5981
,5985
,5968
,5992
,599-6
,6000
1,6005
1,6011
1,6016
,,5974
1,5977
1,5980
1,5982
),598 6
1,5989
),599 3
),599 7
1,8002
),600 7
),597 1
),597 3
),597 5
),597 7
),598 O
),596 3
),598 6
),599 o
),599 4
),599 8
),600 3
1,6009
3,6015
),602 1
D,6028
,5969
,5971
.5973
,5975
1,5977
1,5980
1,5983
),598 6
1,5990
),599 4
),599 9
),600 4
),800 9
),601 5
),602 2
,5867
,5869
,5971
,5973
,5975
D,5865
0,5966
0,5967
0,5969
0,5970
1,5963
1,5964
1,5965
1,5866
1,5968
1,5970
1,5972
),597 4
),597 7
),588 o
=
),598 7
),599 o
),599 5
),599 9
,5962
,5963
,5964
,5965
,5967
,5977
,5980
,5983
,5987
,5881
G
,6000
,6005
,6010
1,6017
0,5972
0,5975
0,5977
0,5980
0,5984
0,5987
0,5881
0,5886
0,6000
0,6006
,5968
,5970
,5972
,5974
,5977
,5980
,5983
1,5986
,5990
1,5994
),596 8
1,5969
),597 1
1,5974
),597 6
),587 9
),598 2
),598 5
)s988
),599 2
1,5967
1,5969
1,5971
1,5973
1,5975
),597 8
),598 1
1,5984
1,5967
),599 o
,6088
,6100
;611 3
,6127
1,6143
1,6160
1,6178
),619 8
—
—
,6048
S056
,6066
,6077
,6088
I,61O1
1,6114
1,6126
1,6144
1,6160
1,6023
),603 O
),603 7
),604 5
),605 4
=
),607 5
),608 6
),609 6
),6111
),612 4
),613 1
),613 8
),614 5
),615 3
),601 3
),601 9
),602 6
),603 3
),604 1
),605 O
),605 9
1,6069
1,6079
),609 1
1,6102
3,6108
L611 4
D,6121
D,6127
D,6036
D,6044
0,6053
IJ,6062
0,6072
0,6082
0,6087
0,6092
0,6097
0,8103
),602 9
),603 7
),604 5
),605 3
),606 2
),607 1
),607 6
1,6061
1,6086
3,6090
1,6023
1,6030
1,6038
1,6046
1;6054
),606 2
),606 7
),607 1
),607 5
),608 c
0,6011
0,6017
0,6023
0,6030
0,6036
0,6043
0,6047
0,6050
0,6054
0,6057
1,6004
),600 9
),601 5
),602 O
),602 6
),603 1
3,6034
3,6037
0,6040
0,6042
1,5998
),600 2
),600 7
),601 1
),601 I?
G
),602 2
),602 t
),602 i
),602 <
),599 6
),600 O
),600 4
),600 8
),601 2
3,6016
3,6018
2,6020
D,6021
D,6023
0,6024
0,6025
0,6026
0,6027
0,6028
0,6028
0,5028
0,6027
0,6026
0,6024
),599 4
),599 7
),600 1
),600 5
),600 8
),601 2
),601 3
),6dl 5
),601 6
),601 7
1,6178
1,6167
1,6197
1,6206
L621 6
—————
),622 C
),623 7
),624 7
),625 f
),626 $
@
),629 (
),630 1
—
—
—
.—
—
—
—
),616 o
),616 7
3,6175
2,6182
3,6190
G
0,6205
0,6212
0,621 S
0,622 t
0,623:
0,623:
0,624 !
0,625-
0,625 [
0,626 (
0,626 I
0,626 ;
0,628 !
0,627
0.627
0,6133
0,614 C
0,614 t
0,6155
0,615 S
0,616 !
0,6171
0,617 i
0,618:
0,618 I
0,619:
0,619:
0,620:
0,620 !
0,620 !
0,621
0,621:
0,621
0,621
0,621
0.621
0,6108
0,6113
0,6119
0,6124
0,8129
0,6134
0,6138
0,6143
0,6147
0.6151
D,6095
0,6100
0,6105
0,610 ~
0,6114
0,611 t
0,6122
0,612 t
0,612$
0.613 S
),608 4
),608 t
),609 S
),609 (
),610 (
1,610 ~
),610 i
3611 ‘
D,611 I
0,611 t
0,6060
0,6063
0,6066
0,6069
0,6072
0,6074
0,6076
0,6078
0,608 c
0,6081
0,6045
0,6047
0,605 C
0,605:
0,6054
0,605:
0,605 (
0,605 i
0,605 [
0,605 [
),603 I
),603 ;
),603 ~
),603 !
1,603 t
G
!),603 ;
D,603 (
0,603 (
0,603 !
1,6018
3,6019
3,6020
D,602 O
0,6020
G
0,601$
0,601 t
0,601 f
0,6014
—————
——————————
0,615 t
0,615 f
0,616 (
0,6162
0,616 ~
0,616:
0,616 !
0,616 ~
0,616:
0,615 !
0.615 I
0,613 !
0,613 [
0,613$
0,614 (
0,614 ‘
0,614 ‘
0,614 [
0,613 I
0,613 !
0,613
0.612 !
D,611 I
0,612 I
0,612
0,612
0,612
0,612 I
0,611
0,611
0,611
0,610
0.610
0,6081
0,6081
0,6081
0,607$
0,607 i
0,607 ~
0,607 ‘
0;606 t
0,606 (
I 0,605:
I 0.604 ~
0,605 i
0,605 [
0,6054
0,605:
0,604 !
0,604 I
0,603 !
0,603:
0,602 I
0,601
0,600
0,603:
0,603
0,602 i
0,602
0,601
K
0,600
0,600
0,599
0,598
0,596
0,6022
0,6019
0,6016
0,6011
0,6006
0,6000
0,5993
0,5984
0,5975
0,5964
0,5951
0,6011
0,600 [
0,600 ~
0,599 (
0,599:
0,598 t
0,597 I
0,596 !
0,595 !
0;594 :
——————
%NOTE TNs table is givenfor convenience.The valueagivenare not intendedfor m’edseinterwdation.Extratmlationis not Iwnnlttad.
31
IS 15675:2006
Table14 Orifice Plate with Flange Tappings -Dkcharge Coefficient, C,for D= 200 mm
iam->ter Discharge cOeffiCieftt, C, for &?DeqUa[ toatio
P 5XI03 1X164 2X194 3XI04 5XI04 7X104 1 x 105 3 x 105 1 x 106 1 x 107 1 Xloe w
),10 0,6005 0,5989 0,5979 0,5975 (),597 1 0,5969 0,5%8 0,5965 0,5963 0,5963 o,$jg62 o,5962
),12 0,6012 0,5993 0,5962 0,5977 0,5973 0,5971 0,5969 0,5966 0,5964 0,5963 0,5963 0,5963
),14 0,6019 0,5998 0,5985 0,5980 (),597 5 0,5973 0,5971 0,5967 0,5966 0,5964 (),596 4 0,5964
1,16 0,6026 0,6003 0;5989 0,5963 0,5978 0,5975 0,5973 0,5969 0,5967 0,5966 0,5965 IJ,5965
),18 0,6033 0,6008 0,5993 0,5986 0,5981 0,5978 0,5975 0,5971 0,5969 0,5987 0,5967 0,5967
),20 0,6041 0,6014 0,5997 0,5990 0,5984 0,5981 0,5978 0,5973 0,5971 0,5969 0,5968 0,5968
),22 0,6050 0,6020 0$001 0,5994 0,5987 015964 0,5981 0,5976 (),597 3 0,5971 .fJ,597~ 0,5970
),24 0,6058 0,6026 0,6006 0,5998 0,5991 0,5987 0,5984 0,5978 0,5975 0,5973 0,5972 -(),597 2
),26 0,6068 0,6033 0,6011 0,6003 (),599 5 0,5991 0,5988 0,5961 0,5978 ‘0,597 5 0,5975 f),5974
1,28 0,6078 0,61WI 0,6017 0,6008 0,6000 0,5995 0,5992 0,5985 7),598 1 0,5976 IJ,5977 o,5976
),30 0,6089 0,6049 0,6024 0,6014 0,6005 0,6000 0,5996 0,598”8 0,5984 ‘o,5981 0,5980 0,5979
2,32 0,6101 0,6058 0,6031 0,6020 0,6010 0,6005 0,6001 0,5992 0,5988 0,5984 0,5983 0,5962
1,34 0,6114 0,6067 0,6038 0,6027 0,6016 0,6011 0,6006 0,5997 0,5992 0,5967 0,5986 0,5985
3,36 0,6128 0,6078 0,6047 0,6034 0,6022 0,6017 0,6012 0,6002 0,5996 0,5991 0,5989 0,5966
3,38 0,6144 0,6089 0,6056 0,6042 0,6029 0,6023 0,6018 0,6007 o,60fJo 0,5995 O,sgg3 (),fjgg 1
1,40 — 0,6102 0,6065 0,6051 0,6037 0,6030 0,6024 0,6012 0,6005 0,5999 0,5997 0,5995
3,42 — 0,6115 0,6076 0,6060 0,6045 0,6038 0,6031 0,6018 0,6010 0,6fX) 3 o,60f31 o,5gg 8
3,44 — 0,6129 0,6087 0,6070 0,6054 0,6045 0,6038 0,6024 0,6015 0,6008 0,6004 o,6@32
D,46 — 0,6145 0,6099 0,6080 0,6063 0,6054 0,6046 0,603.0 0,6021 0,6012 o,~ 8 o,60f) 5
0,46 — 0,6161 0,6111 0,6091 0,6072 0,6062 0,6054 0,6037 0,6026 0,6016 (),601 2 0,600 g
0,50 — 0,6179 0,6124 0,6102 0,6082 0,6071 0,6062 0,6043 0,6032 0,6021 0,6016 (),601 2
0,51 — 0,6168 0,6131 0,6108 0,6087 0,6076 0,6067 0,6047 0,6034 0,6023 0,6018 0,6013
0,52 — 0,6197 0,6136 0,6114 .0,6092 0,6081 0,6071 0,6050 0,6037 0,6025 0,6019 0,6014
0,53 — 0,6206 0,6145 0,612.0 0,6097 0,6085 0,6075 0,6053 0,6039 0,6026 0,6021 0,6015
0,54 — 0,6216 0,6152 0,6126 0,6102 0,6090 0,6079 0,6056 0,6042 0,6028 0,6022 0,6016
0,55 — — 0,6159 0,6132 0,6107 0,6094 0,6083 0,6059 0,6044 0,6030 0,6023 0,6017
0,56 — — 0,6166 0,6138 0,6112 0,6099 0,6067 0,6062 0,6046 0,6031 0,6024 0,6018
0,57 — — 0,6174 0,6145 0,6117 0,6103 0,6091 0,6065 0,6048 0,6032 0,6025 0,6018
0,58 — — 0,6181 0,6151 0,6122 0,6107 0,6094 0,6067 0,6050 0,6033 0,6025 0,6018
0,59 — — 0,6188 0,6156 0,6127 0,6111 0,6098 0,6070 0,6051 0,6033 0,6025 0,6018
0,60 — — 0,6195 0,6162 0,6131 0,6115 0,6101 0,6072 0,6052 0,6034 0,6025 0,6017
0,61 — — 0,6202 0,6168 0,6135 0,6119 0,6104 0,6073 0,6053 0,6033 .0,6024 0,6016
0,62 — — 0,6209 0,6173 0,6139 0,6122 0,6107 0,6075 0,6053 0,6033 0,6023 r),al 4
0,63 — — 0,6216 0,6178 0,6143 0,6125 0,6109 0,6076 0,6053 0,6032 0,6022 0,6012
0,64 — — 0,6222 0,6163 0,6147 0,6126 0,6111 0,6076 0,6053 0,6030 0,6019 0,600 g
0,65 — — 0,6226 0,6188 0,6150 0,6130 0;611 3 U,6076 0,6052 0,6028 0,6016 0,6006
0,66 — — 0,6234 0,6192 0,6152 0,6132 0,6114 0,6075 0,6050 0,6025 0,6013 0,6002
0,67 — — 0,6239 0,6195 0,6154 0,6133 0,6114 0,607-4 0,6047 0,6021 0,6009 O,sgg 7
0,68 — — 0,6244 0,6196 0,6155 0,6133 0,6114 0,6072 0,6044 0,60f 6 0,6003 0,599 I
0,69 — — 0,6248 0,6201 0,6156 0,6133 0,6112 -0,6069 0,6040 0,6011 0,5997 o,5g64
0,70 — — 0,6252 0,6202 0,6155 0,6131 0,6110 0,6065 0,6035 0,6004 0,5990 0,5976
0,71 — — 0,6255 0,6203 0,6154 0,6129 0,6107 0,6060 0,6028 0,5986 0,5982 0,5967
0,72 — — 0,6257 0,6203 0,6152 0,6126 0,6103 0,6054 0,6021 0,5988 0,5972 O,sgs 7
0,73 — — 0,6258 0,6202 0,6149 0,6122 0,6098 0,6047 0,6012 0,5977 0,596 I 0,5945
!3,74 — — 0,6258 0,6199 0,6145 0,6116 0,6092 0,6038 0,6002 0,5966 0,5949 0,5932
0,75 — — 0,6256 0,6196 0,6139 0,6110 0,6084 0,6026 0,5991 0,5953 0,5935 0,5917
NOTE This table is given for mnvenisnce. The values given are not intended for precise interpolation. Extrapolation ia not permilted.
32
IS 15675:2006
Table 15 Orifice Plate with FlangeTappings — Discharge Coefficient, C,for D= 250 mm
fe; Discharge coefficient, C, for R@Dequal toBtio
P 5 x 103 1 X.104 2X104 3XI04 5X104 7 x 104 1 x 10$ 3 x 10’ 1 x 106 1 x To? 1 x 106 m
,10 0,6005 0;5989 0,5979 0,5975 0,5971 0,5969 0,5968 0,5965 0,5964 0,5963 0,5963 0,5963
,,12 0,6012 0,5994 0,5982 0,5977 0,5973 0,5971 0,5970 0,5966 0,5965 0,5964 0,5963 0,5963
,14 0,6019 0,5998 0,5985 0,598.0 0,5976 0,5973 0,5971 0,5968 0,5966 0,5965 0,5965 0,5964
1,16 0,6026 0,6003 0,5989 0,5983 0,5978 095976 0,5974 0,5969 0,5967 0,5966 0,5966 0,5966
1,18 0,6034 0,6009 0,5993 0,5987 0,5981 0,5978 0,5976 0,5971 0;5969 0;5968 0,5967 0,5967
1,20 0,6042 0,6014 0,5997 0,5990 0,5964 0,5981 0,5979 0,5974 0,5971 0,5969 0,5969 0,5969
1,22 0,6050 0,6020 0,6002 0,5994 0,5988 0,5984 0,5981 0,5976 0,5973 0,5971 0,5971 0,5971
1,24 0,6059 0,6027 0,6007 0,5999 0,5991 0,5988 0,5985 0,5979 0,5976 0,5974 0,5973 0,5973
1,26 0,6068 0,s034 0,6012 0,6004 0,5996 0,5992 0,5988 0,5982 0,5978 0,5976 0,5975 0,5975
),28 0,6079 0,6041 0,6018 0,6009 0,6000 0,5996 0,5992 0,5985 0,5981 0,5979 0,5978 0,5977
),30 0,6090 0,6049 0,6025 0,6015 0,6005 0,6001 0,5997 0,5989 0,5985 0,5982 0,5981 0,5980
),32 0,6102 0;6058 0,6032 0,6021 0,6011 Q,6006 0,6002 0,5993 0,5988 0,5985 0,5984 0,5983
),34 0,6115 0,6068 0,6039 0,6028 0,6017 0,6011 0,6007 0,5998 0,5992 0,5988 0,5987 0,5986
),36 — 0,6079 0,6047 0,6035 0,6023 0,6017 0,6012 0,6002 0,5997 0,5992 0,5990 0,5989
),36 — 0,6090 0;6056 0,6043 0,6030 0,6024 0,6018 0;6007 0,6001 0,5996 0,5994 0,5992
),40 — 0,6102 0,6066 0,6051 0,6038 0,6031 0,6025 0,6013 0,6006 0,6000 0,5997 0,5995
),42 — 0,6116 0,6076 0,606.1 0,6046 0,6038 0,603”2 0,6019 0,6011 0,6004 0,6001 0,5999
),44 — 0,6130 0,6087 0,6070 0,6054 0,6046 0,6039 0,6025 0,6016 0,6008 0,6005 0,6002
1,46 — 0,6145 0,6099 0,6081 0,6063 0,6054 0,6047 0,6031 0,6021 0,6012 0,6009 0,6006
),48 — 0,6162 0,6112 0,6091 0,6072 0,6063 0,6055 0,6037 0,6026 0,6017 0,6013 0,600-9
3,50 — — 0,6125 0,6103 0,6082 0,6072 0,6063 0,6044 0,6032 0,6021 0,6016 0,6012
3,51 — — 0,6131 0,6108 0,6087 0,6076 0,6067 0,6047 0,6034 0,6023 0,6018 0,6013
D,52 — — 0,6138 0,6114 0,6092 0,6081 0,6071 0,6050 0,6037 0,6024 0,6019 0,60? 4
0,53 — — 0,6145 0,6120 0,6097 0,6085 0,6075 0,6053 0,6039 0,6026 0,6021 0.6015
0,54 — — 0,6?52 0,6126 0,6102 0,6089 0,6079 0,6056 0,6041 0,6028 0,6022 0,601.6
0,55 — — 0,6159 0,6132 0,6107 0,6094 0,6083 0,6059 0,6044 0,6029 0,6023 0,6017
0,56 — — 0,6166 0,6138 0,6112 0,6098 0,6086 0,6061 0,6045 0,6030 0,6023 0,6017
0,57 — — 0,6173 0,6144 0,6116 0,6f02 0,6090 0,6064 0,6047 0,6031 0,6024 0,6017
0,5 8— — 0,6180 0,6150 0,6121 0,6106 0,8093 0,6066 0,6049 0,6032 0,6024 0,6017
0,59— — 0,6187 0,6155 0,6125 0,6110 0,6097 0,6066 0,6050 0,6032 0,6024 0,6016
0,6o— — 0,619 4 0,6161 0,6130 0,6114 0,6100 0,6070 0,6051 0,6032 0,6023 0,6015
0,6 l— — 0,620 1 0,6166 0,6?34 0,61i 7 0,610 3 0,6071 0,6051 0,6031 0,6023 0,6014
0,62— .— 0,620 7 0,6171 0,613 8 0,612 0 0,610 5 0,6072 0,6051 0,6031 0,6021 0,6012
0,63— — 0,621 4 0,617 6 0,614 1 0,612 3 0,610 7 0,607 3 0,6051 0,602 9 0,601 9 0,6010
0,64 — — 0,622 0 0,616 1 0,614 4 0,612 5 0,610 9 0,607 3 ‘0,6050 0,602 7 0,601 7 0,6006
0,65— — 0,622 6 0,618 5 0,614 7 0,612 7 0,611 0 0,607 3 0,6048 0,602 4 0,601 3 0,6003
0,66— — 0,623 1 0,618 9 0,614 9 0,612 8 0,611 0 0,6072 0,6046 .0,602 1 0,600 9 0,5996
0,67— — 0,623 6 0,619 2 0,615 0 0,612 9 0,811 0 0,607 0 0,6043 0,601 7 0,600 4 0,5993
0,68— — 0,624 0 0,619 4 0,615 1 0,612 9 0,610 9 0,6067 0,6039 0,601 2 0,599 9 0,5986
0,69— — — 0,619 6 0,615 1 0,612 8 0,610 7 0,606 4 0,6035 0,600 5 0,599 2 0,5979
0,7o— — — 0,619 7 0,615 0 0,612 6 0,610 5 D,605 9 0,602 9 0,599 8 0,598 4 0,5970
0,7 l— — — 0,819 7 0,614 8 0,612 3 0,610 1 0,605 4 0,602 2 0,599 0 0,597 5 0,5961
0,72— — — 0,619 6 0,614 5 0,611 9 0,609 6 0,604 7 0,601 4 0,598 0 0,596 5 0,5950
0,73— — — 0,619 4 0,614 1 0,611 4 0,609 0 0,603 9 0,600 4 0,596 9 0,595 3 0,5937
0,74 — — — 0,619 1 0,613 6 0,610 8 0,608 3 0,602 9 0,5994 0,595 7 0,594 0 0,5923
0,75 — — — 0,618 7 0,813 0 0,610 0 0,607 4 0,601 8 0,598 1 0,594 3 0,592 5 0,5908
‘NOTE This table is given for mnvenience. The values given arenot intended for precise intsrpo16tion. EXII’@6tiOn is not perrnlited.
33
IS 15675:2006
Table 16 Orifice Plate with Flange Tappings — Discharge Coefficient, C,for D= 375mm
iam-3ter Discharge coefficient, C, for ReD equai toatio
P 5 x 1.03 1X104 2XI04 3 x 104 5XI04 7 x 104 1 x 105 3X105 1 x 106 1 x 107 1 x 108 m
),10 0,6006 0,5989 0,5979 0,5975 0,5971. 0,5970 0,5968 0,5965 0,5964 0,5963 rJ,5g63 o,5963
),12 0,6013 0,5994 0,5962 0,5978 0,5974 0,5972 0,5970 “0,596 7 0,5965 0,5964 0,5964 0,5964
1,14 0,6020 0,5999 0,5986 0,5981 0,5976 0,5974 0,5972 0,5968 0,5966 0,5965 0,5965 0,5965
),16 0,6027 0,6004 0,5990 0,5984 0,5979 0,5976 0,5974 0,5970 0,5968 0,5967 0,5966 0,5966
),18 0,6035 0,6009 0,5994 0,5987 0,5982 0,5979 0,5977 0,5972 0,5970 0,5968 0,5968 0,5968
),20 0,6042 0,6015 0,5996 0,5991 0,5985 0,5982 0,5979 0,5974 0,5972 0,5970 0,5970 0,5969
),22 0,6051 0,6021 0,6003 0,5995 0,5988 0,5985 0,5982 0,5977 0,5974 (),597 2 0,5972 o,5g7 1
1,24 0,6060 0,6028 0,6008 0,600”0 0,5992 0,5989 0,5Q86 0,5980 0,5977 0,5974 (),597 4 lJ,5g73
1,26 0,6069 0,6035 0,6013 0,6005 0,5997 0,5993 0,5989 0,5983 0,5979 0,5977 0,5976 o,5g76
),28 0,6080 0,6042 0,6019 0,6010 0,6001 0,5997 0,5993 0,5986 0,5983 0,5960 0,5979 0,5976
3,30 — 0,60.51 0,6026 0,6016 0,6006 0,6002 0,5998. 0,5980 0,5986 0,5983 0,5962 o,5g8 1
0,32 — 0,6060 0,6033 0,6022 0,6012 0,6007 0,6003 0,5994 0,5990 0,5986 0,5985 0,5984
>,34 — 0,6069 0,6040 0,6029 0,6018 0,6013 0,6008 0,5999 0,5994 0,593 g 0,5988 0,5g87
11,36 — 0,6080 0,6049 0;6036 0,6024 0,6019 0,6014 0,6004 0,5998 0,5993 0,5991 C3,!jggo
0,38 — 0,6091 0,6058 0,6044 0,6031 0,6025 0,6020 0,6009 0,6002 0,5997 0,5995 i),5993
2,40 — — 0,6067 0,6053 0,6039 0,6032 0,6026 0,6014 0,6007 0,6001 (),599 g 0,5997
0,42 — — 0,6078 0,6062 0,6047 0,603”9 0,6033 0,6020 0,6012 0,6005 0,6002 0,6000
9,44 — — 0,6089 0,6071 0,6055 0,6047 0,6040 0$026 0,6017 0,6009 0,6006 0,6003
0,46 — — 0,6100 0,6082 0,6064 0,6055 0,6048 0,6032 0,6022 0,60f 3 0,6010 l),~i) 7
0,48 — — 0,6113 0,6092 0,6073 0,6064 0,6055 0,603-8 0,6027 0,6018 0,6013 .0,6010
0,50 — — 0,6125 0,6103 0,6083 0,6072 0,6063 0,6044 0,6032 0,6021 0,6017 0,6012
0,51 — — 0,6132 0,6109 0,6088 0,6077 0,6067 0,6047 0,6035 0,6023 0,6018 0,6014
0,52 — — 0,6139 0,6115 0,6092 0,6081 0,6071 0,6050 0,6037 0,6025 ‘0,601 g 0,6015
0,53 — — 0,6145 0,6121 0,6097 0,6085 0,6075 0,605-3 0,6039 0,6026 0,6021 0,6015
0,54 — — 0,6152 0,6126 0,6102 0,6090 0,6079 0,6056 0,6041 0,6028 0,6022 0,6016
0,55 — — 0,6159 0,6132 0,6107 0,6094 0,6082 0,6056 0,6043 0,6029 0,6022 0,6017
0,56 — — 0,6166 0,6138 0,6111 0,6098 0,6086 0,6061 0,6045 0,6030 0,6023 0,6017
0,57 — — — 0,6144 0,6116 0,6102 0,608”9 0,6063 0,6047 0,6030 0,6023 0,6017
0,58 — — — 0,6149 0,6120 0,6106 0,6093 0;6065 0,6048 0,6031 0,6023 0,6016
0,59 — — — 0,6155 0,6124 0,6109 0,6096 0,6067 0,6049 0,6031 0,6023 0,6015
0,60 — — — 0,6160 0,6128 0,6112 0,6098 0,6069 0,6049 0,6030 0,6022 0,6014
0,61 — — — 0,6165 0,6132 0,6116 0,6101 0,6070 0,6050 0,6030 0,6021 0,6012
0,62 — — — 0,6170 0,6136 0,6118 0,6103 0,6070 0,6049 0,6028 0,601.9 0,6010
0,63 — — — 0,6174 0,6139 0,6121 0,6105 0,6071 0,6048 0,6026 0,60j 7 0,6007
0,64 — — — 0,6178 0,6141 0,6122 0,6106 0,6070 0,6047 0,6024 0,6014 0,8003
0,65 — — — 0,6182 0,6143 0,6124 0,6106 0,6069 0,6045 0,6021 0,6010 0,5999
0,66 — — — 0,6185 0,6145 0,6124 0,6106 0,6068 0,6042 0>6017 0,6005 0,5994
0,67 — — — 0,6186 0,6146 0,6124 0,6106 0,6065 0,6039 0,6012 0,6000 0,5988
0,68 — — — 0,6190 0,6146 0,6124 0,6104 0,6062 0,6034 0,6006 .0,5993 0,5981
0,69 — — — — 0,6145 0,6422 0,6102 0,6058 0,6029 0,6000 o,5g86 0,5973
0,70 — — — — 0,6144 0,6120 0,6098 0,6053 J),8022 0,5992 0,5977 0,5964
0,71 — — — — 0,6141 0,6116 0,6094 0,6046 0,6015 0,596”2 0,5966 0,5953
0,72 — — — — 0,6138 0,6tl 1 0,6083 0,8039 0,6006 0,5972 0,5956 0,5941
0,73 — — — — 0,6133 0,6105 0,6081 0,6029 0,5995 0,5960 0;5944 0,5928
0,74 — - “— — 0,6126 0,6098 0,6073 0,6019 0,5983 0,5946 0,5929 0,5913
0,75— — — — 0,6119 0,6089 0,6063 0,6007 0,5969 0,5931 (),591 3 0,5696—. —
34
IS 15675:2006
Table 17 Orifice Plate with Flange Tappings — Discharge Coefficient, C,for D= 760 mm
larn-Iter Discharge coefficient, C, for &?DeqUal totilo
b 5X1O’ 1X16’ 2X104 3X104 5 x 10’ 7 x 10’ 1 x 105 3 x 105 1 x 106 1 x 10’ 1 x 106 m
)110 0,6006 0,5990 0,5979 0,5975 0,5972 0,5970 0,5969 0,5966 0,5964 0,5963 0,5963 0,5963
),12 0,6013 0,5994 0,5983 0,5978 0,5974 0,5972 0,5970 0,5967 0,5965 0,5964 0,5964 0,5964
1,14 0,6020 0,5999 0,5986 0,5961 0,597 ? 0,5974 0,5972 0,5969 0,5967 0,5966 0,5966 0,5965
1,16 0,6028 0,6005 0,5990 0,5965 0,5979 0,5977 0,5975 0,5971 0,5969 0,5967 0,5967 0,5967
1,18 0,6035 0,6010 0,5994 0,5988 0,5962 0,5960 0,5977 0,5973 0,5970 0,596.9 0,5969 0,5968
1,20 — 0,6016 0,5999 0,5992 0,5986 0,5983 0,5960 0,5975 0,5973 0,5971 0,5971 0,5970
1,22 — 0,6D22 0,6004 0,5996 D,5989 0,5986 0,5983 0,5978 0,597 !5 0,5973 0,5973 0,5972
1,24 — 0,6029 0,6009 0,6001 0,5993 0,5990 0,5987 0,5981 0,5978 0,5976 0,5975 0,5975
),26 — 0,6036 0,6014 0,6006 0,5998 0,5994 0,5991 0,5984 0,5981 0,5976 0,5977 0,5977
),28 — — 0,6020 0,6011 0,6003 0,5998 0,5995 0,5986 0,5984 0,5981 0,5980 0,5960
),30 — — 0,6027 0,6017 0,6008 0,6003 0,5999 0,5992 0,5987 0,5984 0,5983 0,5982
),32 — — 0,6034 0,6023 0,6013 0,6008 0,6004 0,5996 0,599”1 0,5987 0,5966 0,5985
),34 — — 0,6042 0,6030 0,6020 0,6014 0,6010 0,6000 0,599:5 0,5991 0,5990 0,5988
),36 — — W35 o 0,603:6 0,6026 0,6020 0,6015 0,6005 0,5999 0,5995 0,5993 0,5992
),36 — — 0,6059 0,6046 0,6033 0,6027 0,6021 0,6010 0,6004 0,5999 0,5997 0,5995
),40 — — — 0,6054 0,6041 0,6034 0,6028 0,6018 0,6009 0,6003 0,6000 0,5998
),42 — — — 0,6064 0,6049 0,6041 0,6035 0,6022 0,6014 0,6007 0,6004 0;6002
),44 — — — 0,6073 0,6057 0,6049 0,6042 0,6027 0,6019 0,6011 0,6008 0,6005
),46 — — — 0,6084 0,6066 0,6057 0,6049 0,6034 0,6024 0,6015 0,6012 0,6006
),48 — — — 0,6094 0,6075 0,6065 0,6057 0,60d O 0,6029 0,6019 0,6015 0,6011
),50 — — — — 0,6064 0,6074 0,6065 0,8046 0,6034 ‘0,602 3 0,6016 0,6014
),51 — — 0,6069 0,6078 0,6069 0,6049 0,6036 0,6025 0,6020 0,607’5
),52 — —. — — 0,6094 0,6082 0,6073 0,6052 0,6039 0,6026 0,6021 0,6016
),53 — — — — 0,6099 0,6087 0,6076 0,6054 0,6041 0,6028 0$022 0,6017
3,54 — — — — 0,6103 0,6091 0,6080 0,6057 0,6043 0,6029 0,6023 0,6017
3,55 — — — — 0,6108 0,6095 0,6084 0,6060 0,6044 0,6030 0,6024 0,6018
3,56 — — — — 0,6112 0,6099 0,6067 0,6062 0,6046 0,6031 0,6024 0,8018
0,57 — — — — 0,8117 0,6103 0,6090 0,6064 0,6047 0,6031 0,6024 0,6017
0,58 — — — — 0,6121 0,6106 0,6093 0,6068 0,6048 0,6031 0,6024 0,6017
D,59 — — — — 0,6125 0,6110 0,6096 0,6068 0,6049 0,6031 0,6023 0,6016
0,60 — — — — 0,6129 0,6113 0,6099 0,6069 0,6050 0,6031 0,6022 0,6014
0,61 — — — — 0,6132 0,6116 0,6101 0,6070 0,6050 0,6030 0,6021 0,6012
0,62 — — — — 0,6136 0,6118 0,6103 0,6070 0,6049 0,6028 0,6019 0,6010
0,63 — — — — — 0,6120 0,6104 0,6070 0,6048 0,6028 0,6016 0,6006
0,64 — — — — — 0,6122 0,6105 0,6069 0,6046 0,6023 0,6013 0,6003
0:65 — — — — — 0,6123 0,6105 0,6068 0,6044 0,6020 0,6009 0,5998
0,66 — — — — — 0,6123 0,6105 0,6066 0,6041 0,6015 0,6004 0,5992
0,67 — — — — — 0,6123 0,6104 0,6063 0,6037 0,6010 0,5998 0,5986
0,68 — — — — — 0,6122 0,6102 0,6060 0,6032 0,6004 0,5991 0,5979
0,69 — — — — — 0,6119 0,6099 0,6055 0,6026 0,5996 0,598 3 0,5970
0,70 — — — — — 0,611 6 0,609 5 0,6049 0,6019 0,598 8 0,597 4 0,5960
0,71 — — — — — 0,611 2 0,609 0 0,6042 0,6010 0,597 8 0,596 3 0,5949
0,72 — — — — — 0,610 7 0,606 4 0,6034 0,6001 0,596 7 0,595 1 0,5936
0,73— — — — — 0,610 0 0,607 6 0,602 4 0,598 9 0,595 4 0,593 6 0,5922
0,74— — — — — — 0,606 7 0,601 2 0,597 6 0,594 0 0,592 3 0,5906
0,75— — — — — — 0,605 6 0,599 9 0,596 2 0,592 3 0,590 6 0,5888
NOTE Thisfableingivanforconvenieme.Thevaluesgivenarenotintendedforprdea intarpdetion.Extrapolationin nof ~itted.
35
IS 15675:2006
Table 18 Orifice Plate with Flange Tappings — Discharge Coefficient, C,for D = 1000 mm
am-ter Discharge coefficient, C, for ReDequal toItio
P 5XI03 1 x 104 2 x 104 3XI04 5XI04 7 x 104 1 x 105 3 x 105 1 XI06 1 x 107 1 x :0’3 m
,10 0,6006 0,5990 0,5980 0,5976 0,5972 0,5970 0,5969 0,5966 0,5964 0,5963 0,5963 0,5963
,12 0,6013 0,5994 0,5983 0,5978 0,5974 0,5972 (),597 o 0,5967 0,5966 0,5965 0,5964 0,5964
,14 0,6020 0,5999 0,5987 0,5981 0,5977 0,5974 0,5973 0,5969 0,5967 0,5966 0,5966 0,5966
,16 0,6028 0,6005 0,5990 0,5985 0,5980 0,5977 0,5975 0,5971 0,5969 0,5967 0,5967 0,5967
,18 — 0,6010 0,5995 0,5988 0,5963 0,5980 0,5977 0,5973 0,597 I o,5969 0,5969 0,5969
,20 — 0,6016 0,5999 0,5992 0,5986 0,5983 0,5980 0,5975 0,5973. 0,5971 0,5971 0,5971
,22 — 0,6022. 0,6004 0,5996 0,5990 0,5986 0,5984. 0,5978 0,5975 0,5973 (),597 3 0,5973
,24 — 0,6029 0,6009 0,6001 0,5994 0,5990 0,5987 0,5981 0,5978 0,5976 0,5975 13,5975
,26 — — 0,6015 0,6006 0,5998 0,5994 0,5991 0,598-4 0,5981 0,5979 0,5978 0,5977
,28 — — 0,8021 0,601 ‘2 0,6003 0,5999 0,5995 0,5988 0,5984 0,598 I o,598 I 0,5980
,30 — — 0,6027 0,6017 0,6008 0,6004 0,6000 0,5992 0,5988 0,5985 0,5983 0,5983
,32 — — 0,6035 0,6024 0,6014 0,6009 0,6005 0,5996 0,5992 0,5988 0,5987 0,5986
,34 — — 0,6043 0,6031 0,6020 0,6015 0,6010 0,6001 0,5996 0,5991 0,599 () o,5989
,36 — — — 0,6036 0,6027 0,6021 0,6016 0,6006 0,6000 0,5995 0,5994 (),599 2
,36 — — — 0,6046 0,6034 0,6027 0,6022 0,6011 0,60.05 0,5999 0,5997 0,5995
,40 — — — 0,6055 0,6041 0,6034 0,6028 0,6016 0,6009 0,6003 0,600 I 0,5999
,42 — — — 0,6064 0,6049 0,6042 0,6035 0,6022 0,6014 0,6007 0,6005 0,6002
,44 — — — — 0,6056 0,6050 0,6043 0,6028 0,6019 0,6012 0,6009 0,6006
,46 — — — — 0,6067 0,6058 0,6050 0,6034 0,6024 0,6016 0,6012 0,6009
1,48 — — — — 0,6076 0,6066 0,6058 0,6040 0,6CJ3O 0,8020 0,6016 0,6012
1,50 — — — — 0,6085 0,6075 0,6065 0,6046 0,6035 0,6024 0,6019 0,6015
1,51 — — — — 0,6090 0,6079 0,6069 0,6049 0,6037 0,6025 0,6020 0,6016
1,52 — — — — 0,6095 0,6083 0,6073 0,6052 0,6039 0,6027 0,6022 0,6017
,53 — — — — 0,8099 0,6087 0,6077 0,6055 0,6041 0,6028 0,6023 0,6017
1,54 — — — — 0,6104 0,6091 0,6081 0,6058 0,6043 0,6030 0,6024 0,6018
1,55 — . — — — 0,6096 0,6084 0,6060 0,8045 0,6031 0,6024 o,60f 6
1,56 — — — — — 0,6099 0,6088 0,6063 0,6047 0,6031 0,6025 0,6018
1,57 . _ _ _ _ 0,6103 0,6091 0,6065 0,6048 0,6032 0,6025 0,6016
),58 _ _ _ _ _ 0,6107 0,6094 0,6067 0,6049 0,6032 0,6024 0,6017
),59 — — — — — 0,6110 0,6097 0,6068 0,6050 0,6032 0,6024 0,6016
),60 — — — — — 0,6113 0,6099 0,6069 0,6050 0,6031 0,6023 0,6015
),61 — — — — — 0,6116 0,6102 0,6070 0,6050 0,6030 0,602 I 0,6013
),62 — — — — — 0,6119 0,6103 0,6071 0,6049 0,6029 0,6019 0,6010
),63 — — — — — 0,6121 0,6105 0,6070 0,6048 0,6026 0,6016 0,6007
),64 — — — — — 0,6122 0;6106 0,6070 0,6047 0,6023 0,6013 0,6003
),65 — — — — — — 0,6106 0,6068 0,6044 0,6020 0,6009 0,5996
J,66 — — — — — — 0,6105 0,6066 0,6041 0,6016 0,6004 0,5993
0,67 — — — — — — 0,6104 0,6063 0,6037 0,6010 0,5998 0,5986
0,68 — — — — — — 0,6102 0,6060 0,6032 0,6004 0,5991 0,5979
0,69 — — — — — — 0,6099 0,6055 0,6026 0,5997 0,5983 0,5970
0,70 — — — — — — 0,6095 0,6049 0,6019 0,5988 0,5974 0,5960
0,71 — — — — — — 0,6090 0,6042 0,6010 0,5978 0,5963 0,5949
0,72 — — — — — — .0,6084 0,6033 0,6000 0,5967 0,5951 0,5936
0,73 — — — — — -- 0,6076 0,6024 0,5989 0,5954 0,5938 0,5922
0,74 — — — — — — 0,6066 0,6012 0,5976 0,5939 0,5922 0,5906
0,75 — — — — — — 0,6055 0,5999 0,5961 0,5923 (),590 5 0,5887
NOTE This table is given for mnvanience. The values given are not intended for precise interpolation. Extrapolation is not permitted,
36
>
IS 15675:2006
Table 19 Orifice Plates — Expansibility (Expansion) Factor, &
(
(
(
(
(
(
(
(
(
t
I
I
(
I
I
NOTE This table is given for convenience. The values given are not intended for precise interpolation. Extrapolation is not permitted.
Diameter ratio Expansibility [expansion] factor,s, forp2/pl equal to
P P’ 0;98 0,96 0,94 0,92 0,90 0,85 0,80 0,75
forx=l,2
0,1000 0;000 1 0,9941 0,9883 0,9824 0,9764 0,9705 0,9555 0,9404 0,9252
0,5623 0,1000 0,9936 0,9871 0,9806 0,9741 0,9676 0,9511 0,9345 0;9177
0,6687 0,2000 0,9927 0,9653 0,9779 0,9705 0,9631 0,9443 0,9254 0,9063
0,7401 0,3000 0,9915 0,9829 0,9743 0,9657 0,9570 0,9352 0,9132 0,8910
0,7500 0,3164 0,9912 0,9824 0,9736 0,9648 0,9559 0,9335 0,9109 0,8881
for~= 1,3
0,1000 0,0001 0,9946 0,9891 0,9837 0,9782 0,9727 0,9587 0,9446 0,9303
0,5623 0,1000 0,9940 0,9881 0,9621 0,9760 0,9700 0,9547 0,9391 0,9234
0,6687 0,2000 0,9932 0,9864 0;9796 0,9727 0,9658 0,9464 0,9307 0,9128
0,7401 0,3000 0,9921 0,9842 0,9762 0,9682 0,9602 0,9399 0,9193 0,8985
0,7500 0,3164 0,9919 0,9836 0,9756 0,9674 0,9591 0,9383 0,9172 0;8958
for~=l,4
0,1000 0,0001 0,9950 0,9899 0,9848 0,9797 0,9746 “0,961 5 0,9483 0,9348
0,5623 0,1000 0,9945 0,9889 0,9833 0,9777 0,9720 0,9577 0,9431 0,9283
0,6687 0,2000 0,9937 0,9874 0,9810 0,9746 0,9681 0,9518 0,9353 0,9184
0,7401 0,3000 0,9927 0,9653 0,9779 0,9704 0,9629 0,9439 0,9246 0,9050
0,7500 0,3164 0,9925 0,9849 0,9773 0,9696 0,9619 0,9424 0,9226 0,9025
for ~= 1,66
0,1000 0,0001 0,9958 0,9915 0,9872 0,9828 0,9784 0,9673 0,9558 0,9441 ~
0,5623 0,1000 0,9953 0,9906 0,9859 0,9811 0,9763 0,9640 0,9515 0,9386
0,6687 0,2000 0,9947 0,9893. 0,9839 0,9785 0,9730 0,9590 0,9447 0,9301
0,7401 0,3000 0,9938 0,9876 0,9813 0,9749 0,9685 0,9523 0,9357 0,9186
0,7500 0,3164 0,9936 0,9872 0,9808 0,9743 0,9677 0,9510 0,9340 0;9164
ANNEX B
(Foreword and C/ause 12.1)
FLOW CONDITIONERS
B-1 GENERAL
This Annex describes some patented flowconditioners which can be used upstream of orificeplates and the requirements for straight lengthsassociated with them. It describes the Gallagherflow conditioner and NOVA’s design of K-Labperforated plate flow conditioner. It gives thesituations in which the flow conditioners havepassed the compliance test and can be useddownstream of any upstream fitting. It is notintended that the inclusion of the flow conditionersdescribed here should limit the use of other flow
conditioner designs which have been tested andproved to provide sufficiently small shifts indischarge coefficient. These flow conditioners,available commercially, are given as examples ofdevices which have passed the compliance test.This information is given for the convenience ofusers and does not constitute an endorsement bythe standard of this product.
B-2 GALLAGHER FLOW CONDITIONER —COMPLIANCE TESTING
B-2.1 The Gallagher flow conditioner shown
37
IS 1-5675:2006
in Fig. 13 meets the compliance test given in thisstandard and can be used downstream of anyfitting provided that it meets the requiredmanufacturing specification (which shall beobtained from the patent holder) and is installedin accordance with B-2.3.
B-2.2 The Gallagher flow conditioner is coveredby an existing patent. It consists of an anti-swirldevice, a settling chamber and lastly a profiledevice as shown in Fig. 14).
The pressure loss coefficient, K, for the Gallagherflow conditioner depends on the manufacturingspecification of the conditioner; it is approximatelyequal to 2, where K is given by the followingequation:
K=%; pvz
where APC is the pressure loss across theGallagher flow conditioner and vis the mean axialvelocity of thefluid in the pipe.
B-2.3 ~, the distance between the orifice plateand the nearest upstream fitting, is at least equalto 17D.The Gallagher flow conditioner is installedso that ~, the distance between the downstreamend of the Gallagher flow conditioner and the orificeplate, is such that
5D5L, <4-8D
In this location, the Gallagher flow conditioner canbe used for p <0.67.
If 0.67s ~s 0.75, the location of the Gallagher flowconditioner is more restricted, and ~ is equal to
7D*D
In this location, the Gallagher flow conditioner hassatisfied in 7.4.1.7 of ISO 5167-1 for p = 0.75.
The distance to a bend (or bend combination) ora tee is measured to the downstream end of thecurved portion of the nearest (or only) bend or ofthe tee. The distance to a reducer or expander ismeasured to the downstream end of the curvedor conical portion of the reducer or expander.
The locations given in this clause are acceptabledownstream of any fitting. A wider range oflocations for the Gallagher flow conditioner ispermissible if the range of upstream fittings isrestricted or the overall length between theupstream fitting and the orifice plate is increasedor the diameter ratio of the orifice plate is reduced.These locations are not described here.
B-3 NCWA’S DESIGN OF K-LAB PERFORATEDPLATE FLOW CONDfTIONER — COMPLIANCETESTING
B-3.1 NOVA!S design of K-Lab pedorated plateflow conditioner, known as the K-Lab NOVA flowconditioner, shown in Fig. 15 meets the compliancetest of this standard and can be used downstreamof any fitting provided that it meets themanufacturing specification in.B-3.2 and B-3.3 andis installed in accordance with B-3.4.
B-3.2 The.K-Lab NOVA f low conditioner consistsof a plate with 25 bored holes arranged in asymmetrical circular pattern as shown in Fig. 15.The dimensions of the holes area function of thepipe inside diameter, D, and depend on the pipeReynolds number. The hole locations forl?e~2105are given in B-3.3.
The perforated plate thickness, ~ is such that
m :-o”’25Dn0IB_-:-~-
2 — profile device
a = Ommis the nominal pipe diameter
b = length equal to diameter of raised face
ac = 3.2 mm for Dwm = 50 mm to 75 mm tube style
—. —-— . .6.4 mm for Dw. = 100 mm to 450 mm tube Style
12.7 mm for D~. = 500 mm to 600 mmtube style
12.7 mm for Dn. = 50 mm to 300 mm vane style
17.1 mm for D-= 350 mm to 600 mm vane etyle
d = 3.2 mm for Dm. .50 mm to 75 mm
* +
6.4 mm for D- .100 mmto450mmc d 12.7mm for Dmm= 500 mm to 600 mm
e e = direction of flow
“FIG. 13 TYPICAL ARRANGEMENT OF GALLAGHER FLOW CONDITIONER
38
IS 15675:2006
KEY
l—
2—
3—
m
2 NOTE — The 3-8-16 pattern for a
anti-swirl device-tube style option: 19-tube uniformconcentric bundle (it may be pin-mounted)anti-swirl device-vane style option: 8 vanes of lengthO.125f3 to 0.25D, concentric with the pipe (the devicemay be placed at the entrance to the meter run)
profile device: 3-8-16 pattern (see Note)
device is:a) 3 holes on pitch circle diameter 0.15D to 0.1 55D, their
diameter is such that the sum of their areas is 3 percentto 5 percent of the pipe area;
b) 8 holes on pitch circle diameter 0.44D to 0.48D theirdiameter is such that the sum of their areas is,l 9 percentto 21 percent of the pipe are% and
c) 16 holes on pitch circle diameter 0.81 D to 0.85~ theirdiameter is such that the sum of their areas is 25 percentto 29 percent of the pipe area.
FIG. 14 TYPICALCOMPONENTSOF GALLAGHERFLOWCONDITIONER(FACE VIEWS)
1-
1-Fw. 15 THE K-LAB NOVAFLOWCONDITIONER
39
IS 15675:2006
0.125D< tC<0.1 5D. The flange thickness dependson the application; the outer diameter and flangeface surface depend on the flange type and theapplication.
The pressure loss coefficient, K, for the K-LabNOVA flow conditioner is approximately equal to 2,where K is given by the following equation:
K=%+PV2
where
APC = pressure loss across the K-Lab NOVAflow conditioner;
P = density of the fluid in the pipe; and
v = mean axial velocity of the fluid in the pipe.
B-3.3 Hole Locations
B-3.3.1 Providedlhat Re~ -8 x 105, there are:
a) a central hole of diameter 0.186 29D* 0.00077D,
‘ b) a ring of 8 holes of diameter 0.163D* 0.000 77D on a pitch circle diameter of0.5D * 0.5 mm, and
c) a ring of 16 holes of diameter 0.120 3D* 0.000770 on a pitch circle diameter of0.85D * 0.5 mm.
B-3.3.2 Provided that 8 x 105> He. -105, thereare:
a) a central hole of diameter 0.226 64D* 0.00077D,
b) a ring of 8 holes of diameter 0.163 09D* 0.00077D on a pitch circle diameter of0.5D * 0.5 mm, and
c) a ring of 16 holes of diameter 0.124 22D* 0.000 77D on a pitch circle diameter of0.85D * 0.5 mm.
B-3.4 ~the distance between the orifice plate andthe nearest upstream fitting, is at least equal to17D.The K-Lab NOVA fiow conditioner is installedso that ~, the distance between the downst~eamend of the K-Lab NOVA flow conditioner and theorifice piate, is such that
The K-Lab NOVA fiow conditioner can be usedfor @ <0.67. s
The distance to a bend (or bend combination) ora tee is measured to the downstream end of thecurved portion of the nearest (or only) bend or ofthe tee. The distance to a reducer or expanderis measured to the downstream end of thecurved or conical portion of the reducer or theexpander.
The locations given in this subclause areacceptable downstream of any fitting. A widerrange of locations for the K-Lab NOVA fiowconditioner is permissible if the range of upstreamfittings is restricted or the overali length betweenthe upstream fitting and the orifice plate isincreased or the diameter ratio of the orifice plateis reduced. These locations ate not describedhere.
40
..,.
Bureau of Indian Standards
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This Indian Standard has been developed from Doc: No. PG 26 (1017).
Amendments Issued Since Publication
Amend No. Date of Issue Text Affected
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Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002 Telegrams: Manaksanstha
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Regional Offices: Tekphone
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{
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{
23378499,23378561KOLKATA 700054 23378626,23379120
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{
26038432609285
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{
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Printed at Prabhat Offset Press, New Delhi-2
I
I
AMENDMENT NO. 1 DECEMBER 2007TO
IS 15675:2006 FLOW MEASUREMENT OF NATURALGAS AND FLUIDS BY ORIFICE PLATE METERS
(Foreword, third para, line 4) — Substitute ‘American Gas Association’for ‘American gas authority’. .
(PG 26)
ReprographyUni~ BIS, New DdM, India
II
.,’ -.— ‘“
. “e”.! .——.
.
-. -. - .-_..: -=