pipesize calculation

7/29/2019 PipeSize Calculation

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Nominal size[inches]

Outsidediameter[inches]

Outsidediameter [mm]

Wall thickness[inches]

Wall thickness[mm]

Weight [lb/ft] Weight [kg/m]

1/8 0,405 10,3 0,068 1,73 0,24 0,37

1/4 0,540 13,7 0,088 2,24 0,42 0,84

1/2 0,840 21,3 0,109 2,77 0,85 1,27

3/4 1,050 26,7 0,113 2,87 1,13 1,69

1 1,315 33,4 0,133 3,38 1,68 2,50

1 1/4 1,660 42,2 0,140 3,56 2,27 3,39

1 1/2 1,900 48,3 0,145 3,68 2,72 4,05

2 2,375 60,3 0,154 3,91 3,65 5,44

2 1/2 2,875 73,0 0,203 5,16 5,79 8,63


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Wall thickness[mm]


3 3,500 88,9 0,216 5,49 7,58 11,29

3 1/2 4,000 101,6 0,226 5,74 9,11 13,57

4 4,500 114,3 0,237 6,02 10,79 16,07

5 5,563 141,3 0,258 6,55 14,62 21,77

6 6,625 168,3 0,280 7,11 18,97 28,26

8 8,625 219,1 0,322 8,18 28,55 42,55

10 10,750 273,0 0,365 9,27 40,48 60,31

12 12,750 323,8 0,406 10,31 53,52 79,73

14 14 355,6 0,375 11,13 54,57 94,55


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Wall thickness[mm]


16 16 406,4 0,500 12,70 82,77 123,30

18 18 457,0 0,562 14,27 104,67 155,80

20 20 508,0 0,594 15,09 123,11 183,42

24 24 610,0 0,688 17,48 171,29 255,41

32 32 813,0 0,688 17,48 230,08 34

SCH40 UPWARDS

SCH20 DOWNWARDS





Wall thickness[mm]


8 8,625 219,1 0,250 6,35 22,36 33,31


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Wall thickness[mm]


10 10,750 273,0 0,250 6,35 28,04 41,77

12 12,750 323,8 0,250 6,35 33,38 49,73

14 14,000 355,6 0,312 7,92 45,61 67,90

16 16,000 406,4 0,312 7,92 52,27 77,83

18 18,000 457,0 0,312 7,92 58,94 87,71

20 20,000 508,0 0,375 9,53 78,60 117,15

22 22,000 559,0 0,375 9,53 86,61 129,13

24 24,000 610,0 0,375 9,53 94,62 141,12

26 26,000 660,0 0,500 12,70 136,17 202,72


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Wall thickness[mm]


28 28,000 711,0 0,500 12,70 146,85 218,69

30 30,000 762,0 0,500 12,70 157,53 234,67

32 32,000 813,0 0,500 12,70 168,21 250,64

34 34,000 864,0 0,750 19,05 266,33 396,93

36 36,000 914,0 0,500 12,70 189,57 282,

This table is for flue gases. It gives values of some physical properties - density and viscosity in relation tothe temperature of gases. It is for following chemical composition:

carbon dioxide CO2 - 13%

water vapour H2O - 11%

nitrogen N2 - 76%

Abbreviations:

t- temperature

- density

cp - specific heat

- dynamic viscosity

- kinematic viscosity


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t cp *106 *106

[O C] [kg/m3] [kJ/kgK] [Pas] [m2/s]

0 1.295 1.042 15.8 12.2

100 0.95 1.068 20.4 21.54

200 0.748 1.097 24.5 32.8

300 0.617 1.122 28.2 45.81

400 0.525 1.151 31.7 60.38

500 0.457 1.185 34.8 76.3

600 0.405 1.214 37.9 93.61

700 0.363 1.239 40.7 112.1


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t cp *106 *106

[O C] [kg/m3] [kJ/kgK] [Pas] [m2/s]

800 0.33 1.264 43.4 131.8

900 0.301 1.29 45.9 152.5

1000 0.275 1.306 48.4 174.3

1100 0.257 1.323 50.7 197.1

1200 0.24 1.34 53 221

This table gives values of some dry air physical properties - density, specific heat and viscosity in relation totemperature and pressure.

Abbreviations:

t- temperature

- density

cp - specific heat

- dynamic viscosity


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ic viscosity

t [O C] -50 0 50 100 150 200 300 400

[kg/m3]

1 bar 1.563 1.275 1.078 0.932 0.8226 0.7356 0.6072 0.517

50 bar 83.79 65.20 53.96 46.25 40.57 36.18 29.80 25.37

100 bar 175.6 131.4 107.1 91.13 79.66 70.92 58.37 49.71

200 bar 340.3 253.7 205.4 174.3 152.2 135.6 111.8 95.41

300 bar 449.3 350.8 288.6 246.7 216.4 193.4 160.3 137.4

cp [kJ/kgK]

1 bar 1.007 1.006 1.008 1.012 1.018 1.026 1.046 1.69

50 bar 1.212 1.112 1.085 1.075 1.055 1.049 1.061 1.08


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t [O C] -50 0 50 100 150 200 300 400

100 bar 1.43 1.216 1.133 1.096 1.078 1.072 1.075 1.09

200 bar 1.623 1.361 1.229 1.161 1.126 1.108 1.099 1.107

300 bar 1.604 1.409 1.282 1.204 1.16 1.135 1.117 1.12

*106[Pas]

1 bar 14.65 17.2 19.61 21.82 23.92 25.85 29.47 32.76

50 bar 16.7 19.42 20.57 22.59 24.4 26.4 29.9 33.1

100 bar 18.3 20.2 21.7 23.4 25.1 26.9 30.4 33.5

200 bar 22.8 23.6 24.4 25.6 26.8 28.5 31.5 34.7


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t [O C] -50 0 50 100 150 200 300 400

300 bar 28.7 27.8 27.5 28.1 28.8 30.1 33.1 36.1

This table gives values of water properties - density, viscosity and specific heat in relation to temperature.For temperatures higher than 100OC, values are for water at boiling conditions.

t- temperature

p - pressure

- density

cp - specific heat

- dynamic viscosity

- kinematic viscosity

t p cp *106 *106

[O C] [bar] [kg/m3] [kJ/kgK] [Pas] [m2/s]

0 1.013 999.9 4.212 1788 1.789

10 1.013 999.7 4.191 1306 1.306

20 1.013 998.2 4.183 1004 1.006


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t p cp *106 *106


30 1.013 995.7 4.174 801.5 0.805

40 1.013 992.2 4.174 653.3 0.659

50 1.013 988.1 4.174 549.4 0.556

60 1.013 983.1 4.179 469.9 0.478

70 1.013 977.8 4.187 406.1 0.415

80 1.013 971.8 4.195 355.1 0.365

90 1.013 965.3 4.208 314.9 0.326

100 1.013 958.4 4.220 282.5 0.295


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t p cp *106 *106


110 1.43 951.0 4.233 259.0 0.272

120 1.98 943.1 4.250 237.4 0.252

130 2.70 934.8 4.266 217.8 0.233

140 3.61 926.1 4.287 201.1 0.217

150 4.76 917.0 4.313 186.4 0.203

160 6.18 907.4 4.346 173.6 0.191

170 7.92 897.3 4.380 162.8 0.181

180 10.03 886.9 4.417 153.0 0.173


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t p cp *106 *106


190 12.55 876.0 4.459 144.2 0.165

200 15.55 863.0 4.505 136.4 0.158

210 19.08 852.8 4.555 130.5 0.153

220 23.20 840.3 4.614 124.6 0.148

230 27.98 827.3 4.681 119.7 0.145

240 33.48 813.6 4.756 114.8 0.141

250 39.78 799.0 4.844 109.9 0.137

260 46.94 784.0 4.949 105.9 0.135


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t p cp *106 *106


270 55.05 767.9 5.070 102.0 0.133

280 64.19 750.7 5.230 98.1 0.131

290 74.45 732.3 5.485 94.2 0.129

300 85.92 712.5 5.736 91.2 0.128

310 98.70 691.1 6.071 88.3 0.128

320 112.9 667.1 6.574 85.3 0.128

330 128.65 640.2 7.244 81.4 0.127

340 146.08 610.1 8.165 77.5 0.127


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t p cp *106 *106


350 165.37 574.4 9.504 72.6 0.126

360 186.74 528.0 13.984 66.7 0.126

370 210.53 450.5 40.321 56.9 0.126

Fluid flow mean velocity and pipe diameter for known flow rate

Velocity of fluid in pipe is not uniform across section area. Therefore a mean velocity is used and it iscalculated by the continuity equation for the steady flow as:

Pipe diameter calculator

Calculate pipe diameter for known flow rate and velocity. Calculate flow velocity for known pipe diameter and flow

rate. Convert from volumetric to mass flow rate. Calculate volumetric flow rate of ideal gas at different conditions

of pressure and temperature.

Pipe diameter can be calculated when volumetric flow rate and velocity is known as:

where is: D - internal pipe diameter; q - volumetric flow rate; v- velocity;A - pipe cross section area.
http://www.pipeflowcalculations.com/flowrate/http://www.pipeflowcalculations.com/flowrate/


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If mass flow rate is known than diameter can be calculated as:

where is: D - internal pipe diameter; w- mass flow rate; - fluid density; v- velocity.

Laminar and turbulent fluid flow regime in pipe, critical velocity

If the velocity of fluid inside the pipe is small, streamlines will be in straight parallel lines. As the velocity offluid inside the pipe gradually increase, streamlines will continue to be straight and parallel with the pipewall until velocity is reached when the streamlines will waver and suddenly break into diffused patterns. Thevelocity at which this occurs is called "critical velocity". At velocities higher than "critical", the streamlinesare dispersed at random throughout the pipe.

The regime of flow when velocity is lower than "critical" is called laminar flow (or viscous or streamline flow).

At laminar regime of flow the velocity is highest on the pipe axis, and on the wall the velocity is equal tozero.

When the velocity is greater than "critical", the regime of flow is turbulent. In turbulent regime of flow there isirregular random motion of fluid particles in directions transverse to the direction on main flow. Velocitychange in turbulent flow is more uniform than in laminar.

In the turbulent regime of flow, there is always a thin layer of fluid at pipe wall which is moving in laminarflow. That layer is known as the boundary layer or laminar sub-layer. To determine flow regimeuseReynolds numbercalculator.

Reynolds number, turbulent and laminar flow, pipe flow velocity

and viscosity

The nature of flow in pipe, by the work of Osborne Reynolds, is depending on the pipe diameter, the densityand viscosity of the flowing fluid and the velocity of the flow. Dimensionless Reynolds number is used, andis combination of these four variables and may be considered to be ratio of dynamic forces of mass flow tothe shear stress due to viscosity. Reynolds number is:

where is: D - internal pipe diameter; v- velocity; - density; - kinematic viscosity;- dynamic viscosity;

Reynolds number calculator

Calculate Reynolds number with this easy to use calculator. Determine if flow is laminar or turbulent. Applicable

for liquids and gases.

This equation can be solved using and fluid flow regime calculator.
http://www.pipeflowcalculations.com/reynolds/http://www.pipeflowcalculations.com/reynolds/http://www.pipeflowcalculations.com/reynolds/http://www.pipeflowcalculations.com/reynolds/


17/22

Flow in pipes is considered to be laminar if Reynolds number is less than 2320, and turbulent if theReynolds number is greater than 4000. Between these two values is "critical" zone where the flow can belaminar or turbulent or in the process of change and is mainly unpredictable.

When calculating Reynolds number for non-circular cross section equivalent diameter (four time hydraulicradius d=4xRh) is used and hydraulic radius can be calculated as:

Rh = cross section flow area / wetted perimeter

It applies to square, rectangular, oval or circular conduit when not flowing with full section. Because of greatvariety of fluids being handled in modern industrial processes, a single equation which can be used for theflow of any fluid in pipe offers big advantages. That equation is Darcy formula, but one factor - the frictionfactor has to be determined experimentally. This formula has a wide application in the field of fluidmechanics and is used extensively throughout on this web site.

Bernoulli equation - fluid flow head conservation

If friction losses are neglected and no energy is added to, or taken from a piping system, the total head, H,which is the sum of the elevation head, the pressure head and the velocity head will be constant for anypoint of fluid streamline.

This is the expression of law of head conservation to the flow of fluid in a conduit or streamline and isknown as Bernoulli equation:

where is: Z1,2- elevation above reference level;p1,2- absolute pressure; v1,2- velocity;1,2- density; g-acceleration of gravity

Bernoulli equation equation is used in several calculators on this site likepressure dropand flow ratecalculator, Venturi tube flow rate meter and Venturi effect calculator and orifice plate sizing and flow ratecalculator.

Pipe flow and friction pressure drop, head energy loss | Darcy

formula

From Bernoulli equation all other practical formulas are derived, with modifications due to energy lossesand gains.

As in real piping system, losses of energy are existing and energy is being added to or taken from the fluid(using pumps and turbines) these must be included in the Bernoulli equation.

For two points of one streamline in a fluid flow, equation may be written as follows:
http://www.pipeflowcalculations.com/pressuredrop/http://www.pipeflowcalculations.com/pressuredrop/http://www.pipeflowcalculations.com/pressuredrop/http://www.pipeflowcalculations.com/venturi/http://www.pipeflowcalculations.com/orifice/http://www.pipeflowcalculations.com/pressuredrop/http://www.pipeflowcalculations.com/venturi/http://www.pipeflowcalculations.com/orifice/


18/22

where is: Z1,2- elevation above reference level;p1,2- absolute pressure; v1,2- velocity;1,2- density; hL -head loss due to friction in the pipe; Hp - pump head; HT - turbine head; g- acceleration of gravity;

Flow in pipe is always creating energy loss due to friction. Energy loss can be measured like static pressuredrop in the direction of fluid flow with two gauges. General equation for pressure drop, known as Darcy'sformula expressed in meters of fluid is:

where is: hL - head loss due to friction in the pipe; f- friction coefficient; L - pipe length; v- velocity; D -internal pipe diameter; g- acceleration of gravity;

To express this equation like pressure drop in newtons per square meter (Pascals) substitution of properunits leads to:

Pressure drop calculator

Calculator based on Darcy equation. Calculate pressure drop for known flow rate or calculate flow rate for known

pressure drop. Friction factor calculation included. Applicable for laminar and turbulent flow, circular or

rectangle pipe.

where is: p - pressure drop due to friction in the pipe; - density; f- friction coefficient; L - pipe length; v-velocity; D - internal pipe diameter; Q - volumetric flow rate;

The Darcy equation can be used for both laminar and turbulent flow regime and for any liquid in a pipe.

With some restrictions, Darcy equation can be used for gases and vapors. Darcy formula applies when pipediameter and fluid density is constant and the pipe is relatively straight.

Friction factor for pipe roughness and Reynolds number in laminar

and turbulent flow

Physical values in Darcy formula are very obvious and can be easily obtained when pipe properties areknown like D - pipe internal diameter, L - pipe length and when flow rate is known, velocity can be easilycalculated using continuity equation. The only value that needs to be determined experimentally is friction

factor. For laminar flow regime Re < 2000, friction factor can be calculated, but for turbulent flow regimewhere is Re > 4000 experimentally obtained results are used. In the critical zone, where is Reynoldsnumber between 2000 and 4000, both laminar and turbulent flow regime might occur, so friction factor isindeterminate and has lower limits for laminar flow, and upper limits based on turbulent flow conditions.

If the flow is laminar and Reynolds number is smaller than 2000, the friction factor may be determined fromthe equation:
http://www.pipeflowcalculations.com/pressuredrop/http://www.pipeflowcalculations.com/pressuredrop/


19/22

where is: f- friction factor; Re - Reynolds number;

When flow is turbulent and Reynolds number is higher than 4000, the friction factor depends on piperelative roughness as well as on the Reynolds number. Relative pipe roughness is the roughness of thepipe wall compared to pipe diametere/D. Since the internal pipe roughness is actually independent of pipediameter, pipes with smaller pipe diameter will have higher relative roughness than pipes with biggerdiameter and therefore pipes with smaller diameters will have higher friction factors than pipes with biggerdiameters of the same material.

Most widely accepted and used data for friction factor in Darcy formula is the Moody diagram. On Moodydiagram friction factor can be determined based on the value of Reynolds number and relative roughness.

The pressure drop is the function of internal diameter with the fifth power. With time in service, the interiorof the pipe becomes encrusted with dirt, scale, tubercles and it is often prudent to make allowance forexpected diameter changes. Also roughness may be expected to increase with use due to corrosion or

incrustation at a rate determined by the pipe material and nature of the fluid.

When the thickness of laminar sub layer (laminar boundary layer) is bigger than the pipe roughness e theflow is called flow in hydraulically smooth pipe and Blasius equation can be used:

where is: f- friction factor; Re - Reynolds number;

The boundary layer thickness can be calculated based on the Prandtl equation as:

where is: - boundary layer thickness; D - internal pipe diameter; Re- Reynolds number;

For turbulent flow with Re < 100 000 (Prandtl equation) can be used:

For turbulent flow with Re > 100 000 (Karman equation) can be used:

where is: f- friction factor; Re - Reynolds number; D - internal pipe diameter; kr - pipe roughness;


20/22

Above equations are used forpressure drop and flow rate calculator.

Static, dynamic and total pressure, flow velocity and Mach number

Static pressure is pressure of fluid in flow stream. Total pressure is pressure of fluid when it is brought to

rest, i.e. velocity is reduced to 0.

Total pressure can be calculated using Bernoulli theorem. Imagining that flow is in one point of stream linestopped without any energy loss Bernoulli theorem can be written as:

If velocity at point 2 v2=0, pressure at point 2 is than total p2=pt:

where is:p - pressure;pt - total pressure; v- velocity; - density;

The difference between total and static pressure represents fluid kinetic energy and it is called dynamicpressure.

Dynamic pressure for liquids and incompressible flow where the density is constant can be calculated as:

where is:p - pressure;pt - total pressure;pd - dynamic pressure; v- velocity; - density;

If dynamic pressure is measured using instruments like Prandtl probe or Pitot tube velocity can becalculated in one point of stream line as:

where is:p - pressure;pt - total pressure;pd - dynamic pressure; v- velocity; - density;

For gases and larger Mach numbers than 0.1 effects of compressibility are not negligible.

For compressible flow calculation gas state equation can be used. For ideal gases, velocity for Machnumber M < 1 is calculated using following equation:
http://www.pipeflowcalculations.com/pressuredrop/http://www.pipeflowcalculations.com/pressuredrop/


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where is: M- Mach numberM=v/c- relation between local fluid and local sound velocity; - isentropiccoefficient;

It should be said that for M > 0.7 given equation is not totally accurate.

If Mach number M > 1, than normal shock wave will occur. Equation for velocity in front of the wave is givenbellow:

where is:p - pressure;pti - total pressure; v- velocity; M- Mach number; - isentropic coefficient;

Above equations are used forPrandtl probe and Pitot tube flow velocity calculator.

Note: You can download complete derivation of given equations

Fluid flow rate for the thermal - heat power transfer, boiler power

and temperature

The flow rate of fluid required for the thermal energy - heat power transfer can be calculated as:

where is: q - flow rate [m3/h]; - density of fluid [kg/m3]; c- specific heat of fluid [kJ/kgK]; T- temperaturedifference [K]; P- power [kW];

Thermal energy calculator

Calculate heat energy and thermal power for known flow rate. Calculate flow rate for known heat energy or

thermal power. Applicable for boilers, heat exchangers, radiators, chillers, air heaters.

This relation can be used to calculate required flow rate of, for example, water heated in the boiler, if thepower of boiler is known. In that case temperature difference in above equation is the change oftemperature of fluid in front and after the boiler. It should be said that efficiency coefficient should beincluded in above equation, for precise calculation.
http://www.pipeflowcalculations.com/prandtl/http://www.pipeflowcalculations.com/prandtl/equations.ziphttp://www.pipeflowcalculations.com/heater/http://www.pipeflowcalculations.com/prandtl/http://www.pipeflowcalculations.com/prandtl/equations.ziphttp://www.pipeflowcalculations.com/heater/


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Above expression is used and can be solved using calculator for thermal energy, heat power and flow ratecalculation

pipesize calculation

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