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Operating manualGuth Throttling Valves VSR

Flow ComponentsCapital EquipmentEngineered Processing Units

Table of Contents

1 Valve Design 03

1.1 General Description 03

1.2 Valve Options 04

2 Functional Description 05

3 Throttling Vavle Installation 06

4 Start-Up 07

5 Changes on the Throttling Valve 07

5.1 Changes pf the C-factor and flow characteristics 07

5.2 Actuation Direction (reversal of the diaphragm actuator) 08

6 Maintenance 08

6.1 Servicing 08

6.2 Replacement of the cone/seat trim 08

6.3 Seal Replacement 09

7 Trouble Shooting 11

7.1 Defects in the Mechanical System (valve) 11

7.2 Defects in the Actuator 13

7.3 Defects on the Regulator 14

© Copyright Page | 02



1. Valve Design

1.1 General Description

GUTH-throttling vavlesm series VST, represent the latest state of regulation/control technology incorporating provenstainless steel valves and actuators.

Regulating/Control Valves can be roughly subdivided into four main elements:

a) Throttling valve housing with function-specific interior trim, consisting of valve spindle and seat ring(s).

b) Lantern housing the spindle seal and spindle guide.

c) Reversible stainless steel diaphram actuator with spring-return mechanism.

d) Positioner, (refer to specific “DigiPos” and “Area” instruction manuals.

The mains elements are displayed in figure 1.

Fig 1: Design of GUTH-throttling valve type VSR.






1.2 Options

A number of options are available for the VSR as detailed below.

Housing Versions

Valve housings consist of spherical bodies made from forged stainless steel having one or two ports to suit duty conditions.The bodies, valve seats and blanks can be joined together by clamps to make up the various configurations required forthe duty conditions such as single L or double Z shaped for modulating, three bodies for flow mixing, three for flowdiversion and three for multi step specially designed cones and seats for high pressure reduction and control. The tophousing is fitted with a sealing connection housing the body seal preventing leakage to atmosphere. As an option the valvecones can be fitted with a soft seal to facilitate shut-off when the valve is closed. For special application the cones andseats can be hardened.

Actuator Lantern Versions

The lantern is the connection piece between the valve housings and the pneumatic actuator, housing a bearing for theheavy duty spindle and second o-ring sealing the valve housing for the atmosphere. The lantern can also be equippedwith with ports for atmospheric sealing by a barrier media such as alcohol or steam. For high operating temperatures alonger lantern with and intermediate section can be supplied. Alternative seals such as Teflon for vacuum and packingfor steam duties are available.

Diaphragm Actuator Version:

Please see “GUTH operation and Maintenance Manual for Multi-spring Diaphragm Actuators”.

Positioner Versions:

Please see “Assembly and Operation Manuals for DigiPos and Positioners Type 824”.


2. Function Description

The standard stroke of the GUTH VSR throttling vavle with multi-spring diaphragm actuator is 20mm and 30mm forthe sizes 25 to 100. The linear motion of the valve spindle is initiated be an actuator shaft which is connected to thediaphragm. Due to the excess pressure in the pressure chamber of the diaphragm, the diaphragm disk performs an axialmotion until the pressure force on the other side. due to the linear characteristic of the springs, the stroke of thediaphragm is about proportional to the built-up air pressure in the actuator. The Digipos positioner controls the airsupply and exhaust by means of solenoid vavles.

To maintain a consistant equilibrium at maximum air flow.

The actuators are supplied as fail-safe open or fail-safe closed, in the fail-safe open position the limit stop of the actuatoris reached and in the case of fail-safe closed the cone is at rest on the valve seat.

The regulating cones have a precisely calculated shape which results from the free cross-section in the annular gap andthe stroke. Depending on the Cv factor the valves operate as linear or an equal percentage characteristic curve with agradient of 1 : 25 or 1 : 40 as shown in figure 2.

In order to obtain perfect regulation the flow direction should be towards the tapered side of the cones.Hermetic sealing between cones is also available on request.

Fig 2



0

0.5

1.0

1.5

1.9

0 10 20 30 40 50 60 70 80 90 100 stroke [%]

0

0.5

1.0

1.5

1.9

0 10 20 30 40 50 60 70 80 90 100 stroke [%]


3. Throttling Vavle Installation

Mounting Environment:

Since the GUTH throttling valves Type VSR are of compact design they can be mounted in any position in the systemwith sufficient space to avoid mechanical and electrical contact with other equipment to prevent thermal transmissionand vibration. Environmental temperature range 0° - 70°c

Mounting Position:

The normal mounting position is vertical, actuator up, however actuator down or horizontal does not impair the valvefunction. In the case of larger valves mounted in the horizontal position additional support may be required for the actuator.

The piston actuator spring chamber vent should be positioned in such a way as to avoid ingress of liquids.

Tube Connections:

All GUTH throttling valves can be equipped with any standard connection fittings to suit Dairy and DIN tubing and flangedin the case of steam applications.

Remove the complete valve plug, actuator and positioner before welding the butt weld end type valve bodies into thesystem. Welding procedures should confirm to hygienic industry standards for preparation and finishing. After completionassemble and check the functions.

Although Guth modulating valves, housings and spindles are extremely robust the influence of tube forces caused bythermal expansion and contraction should be allowed for during installation.Guth modulating valve are high precision valves with a cone and seat mating clearance of 1/100 mm therefore contaminatedproduct lines should be filtered up-stream of the valve.

For inspection and maintenance purposes it is recommended that shut-off valves are fitted up stream and down streamof the modulating valve and in some cases if necessary provide a bypass line around the valve to avoid plant shut-downin the event of a breakdown.

Pneumatic / Electrical connections

Guth modulating valves are supplied as standard with Guth DigiPos electro-pneumatic positioners equipped a push-inair connectors suitable for 4 mm ID plastic air tubing.

Control air supply in accordance with DIN/ISO 8573.1 is required as follows:

Minimum air pressure 6.0 BarSolids content Quality class 3 particle size - Max 5 µmWater content Quality class 4 - 6000 mg/m3Oil content Quality class 5 - 25 mg/m3

For detailed information on the Guth DigiPos electro-pneumatic positioners refer to the operating and maintenance manual




4. Start-Up

Information

Guth modulating valves are delivered completely assembled as per the designed duty specifications.Plant installation is to be carried out as detailed in section 3 of this manual.

Modulating valve function test

After the valve has been installed in the plant function test should be carried out in accordance with this manual and theDigiPos operating manual.

5. MODULATING VALVE CHANGES

5.1 Changes to the CV factor and flow characteristics

The spindle position (stroke) relationship between the free opening cross-section of the cone and the flow volume ofthe liquid or gas depends on the shape and dimensions of the cone as well as that of the seat diameter of the replaceableseat ring as shown in the CV factor characteristic value for the cone/seat combination. If a change in the regulation rangeis required contact Guth South Africa for advice as the cone/seat profile is crucial to the behaviour of the valve see Figure 2.

Trims consisting of seat ring and spindle cones can be changed as follows:

• Piston actuator type with single cone and seat (see VSR versions in the appendix), remove the piston actuator withthe DigiPos electro-pneumatic positioner and spindle from the housing taking care not to damage the cone.

• Membrane actuator type with single cone and seat (see VSR versions in the appendix), remove the piston actuatorwith the DigiPos electro-pneumatic positioner and spindle from the housing taking care not to damage the cone.

• Modulating valves type K 3 mixing version is disassembled by removing the valve from the pipework, remove theclamp securing the lower housing. Unscrew the spindle using a socket wrench and carefully withdraw from thehousings. Split the housings to gain access to the seats.

• Modulating valves type K 4 distribution version is disassembled by removing the valve from the pipework, removethe lower cover assembly and unscrew the lower spindle using a socket wrench to remove the seat ring. Removethe clamps and split the other housing halves to obtain access to the other valve seat ring.

The valve seats are marked with the calculated dimensioning diameter and the spindle cone calculated dimensioningdimensions are marked on the upper shaft area with the identifier L (Linear) or G (Equal Percentage).

The spindle can now be removed from the guide by removing the the two hexagon bolts from the coupling and unscrewingthe coupling half off the spindle.

Assembly of the spindle or a replacement spindle is carried out in the reverse order slightly lubricating the sealing elementsand shaft surface before inserting the spindle into the guide to ensure smooth operation.




When inserting the seat rings replace all the o-rings and ensure that the location areas of the valve housing are cleanand free of burs that could damage the o-rings. Slightly lubricate the o-rings before assembly.

The valve can now be fully assembled ensuring that this is carried out in a clean environment to avoid dirty seat and cone areas.

5.2 Reversal of actuator direction

For reversing the actuating direction of the membrane actuator see the Guth Membrane Operating and Maintenancemanual for multi spring actuators.

6. Maintenance

6.1 Servicing

Although the Guth Modulating valve Type VSR requires low maintenance a regular inspection of the valve is recommended i.e. after every 500 hours to check the following:

• Check for product leakage around the valve body and at the leakage hole located directly under the clamp betweenthe valve housing and the lantern. Replace the seal if required and repair/replace the valve spindle if damaged.

• Check all the air connections for leaks and tighten as necessary.

• Check regulating behaviour to make sure that there is a smooth stroke movement at high signal changes. Slight strokefluctuation will occur around the operating point maintaining the control function. For further information on theelectro-pneumatic positioner refer to the Guth DigiPos Operating and Maintenance manual.

• Check electrical connections by removing the stainless steel positioner cap making sure all terminal are tight. Inspectthe cap interior for moisture and dirt, clean if necessary and replace the o-ring thus insuring the IP 65 rating. Forfurther information refer to the Guth DigiPos Operating and Maintenance manual.

6.2 Replacement of the cone/seat trim

Due to the high flow velocity through the cone gap the seats and cones will gradually be abraded which will lead toimproper regulation behaviour requiring replacement of seat and cone set which can not be avoided.

In the case of the multi stage high pressure reducing modulating valves the seats and cones are hardened to prolongoperating life. For replacement of the seat and cone together with the seal rings refer to section 5.1 of this manual.






6.3 Seal Replacement

All valve elastomers are standard EPDM, Viton or PTFE o-rings together with the soft seal in the cone if fitted.

• Housing

After removing the clamps between the valve housings and valve housing and lantern the the old o-rings can be removedensuring that the o_ring groves are not damaged. Clean the groves and check for damage. Using food grade grease lightlygrease the replacement o-rings and insert in the correct positions. Take care not to damage or over stretch the replacemento-rings. Assemble in the reverse order.

• Spindle

Spindle sealing is of prime importance for hygienic reasons and o-ring replacement is carried out as follows:

Make sure that the spindle sealing area is in perfect condition, if there are braiding marks on the spindle attempt tosmooth the surface using fine emery tape. If the sealing area is badly marked the spindle should be replaced.

The assembly of the vacuum seal is in the following order:O-ringBack to back Teflon lip sealsO-ringWasher.

Make sure that the Teflon lip seals are parallel before being pressed into the seal chamber by means of the suitablysized drift.

In the case of a steam valve packed gland system insert the packing rings evenly and lightly tighter the follower enoughto ensure sealing of the gland. Do not over tighten as this will bind the shaft and impair the regulating behaviour ofthe valve.

In order to extend the seal life lightly lubricate the shaft and seal components with a suitable food grade grease.

• For the positioner seal replacement refer to the Guth DigiPos electronic stroke positioner manual.


Maintenance Schedule




7. Trouble Shooting

7.1 Defects in the mechanical system

• The Guth VSR modulating valve and actuator is of robust design therefore it is highly unlikely to suffer mechanicaldamage. Damage to the spindle/cone seat and the shaft seal can occur and the following describes the causes and remedies.

1. High metal to metal cone/seat seal leakage

Causes

• Seat ring cone sealing area or cone is damaged by a solid particle.• Seat ring cone sealing area or cone is damaged by erosion or cavitation• Valve housing or spindle deformed preventing correct alignment of the cone and seat• Deposits on the seat/cone seat area• Insufficient closing pressure caused by a broken spring, ruptured membrane,obstructed valve spindle or faulty

assembly (also refer to section 7.2).

Error Correction

• Replace defective spindle refer to section 6.2• Replace deformed housing refer to section 6.3• If the spindle is sluggish check and replace the spindle seal and/or the spindle guide in the actuator adaptor• In the steam version valve check that the gland packing is not over tightened or damaged and replace as necessary.• Should the membrane actuator require attention due to broken springs or ruptured membrane refer to the “Operating

and Maintenance Manual for Multi-Spring Membrane Actuators”.• Careful cleaning to remove deposits from the cone/seat area ensuring that no damage is caused to these areas.

2. Unsatisfactory regulation behaviour

Causes

• Spindle movement sluggish and erratic (also refer to section 7.2)

Error Correction

• Refer to section 7.2




3. Unsatisfactory flow characteristics

Drastic increase/decrease in the flow rate or deviation from flow characteristic curve

Causes

• Interference from other equipment in the system• Unsuitable cone shape for the selected process• Sluggish spindle or actuator movement• Damage to cone/seat• Seat ring and spindle not axially aligned because of faulty assembly, damaged spindle or worn/damaged spindle guide

Error Correction

• If the cone/seat is damaged replace as described in section 6.2• Sluggish spindle or actuator movement should be repaired as detailed in item 1 above• Deviation from flow characteristic curve could indicate signal problem from the system process control system,

incorrect instrument voltage or in rare occasions a faulty electronic positioner. Refer to “Operating and MaintenanceManual for DigiPos electronic positioner.

• Check if the flow characteristic can be improved by changing the kvs value refer to section 5.1 and contact GuthSA technical department for assistance.

4. Housing leakage

Causes

• Leakage can occur from time to time from water hammer• System pressure surges• Temperature changes• Ageing of the elastomers and seals.

Error Correction

• Replace all housing and spindle seals• Check for and remedy water hammer




5 High emission noise

High velocity and turbulence through the annular gap can cause vibrations in the spindle and also in some cases in thevalve housings and thus transferred to other valve components. In some cases extreme vibrations can be caused byresonance. The rigid valve housing and the precise spindle guides of the Guth modulating valve usually prevent noiseemissions.

Causes

• Unacceptable pressure drop through the cone/seat.• Incorrect valve adjustment• Abrading of the cone/seat caused by high flow velocity• Faulty spindle adjustment or deposits on the seat.• Worn or damaged spindle guide• Loose spindle couplings.

Error Correction

• Fitting a different cone/seat combination• Fitting a double spindle guide• In extreme operating conditions special measures may be necessary such as the use of a multi stage valve.• If there is noise emission due to wear, replace the worn components as detailed in chapter 6 of this manual.• Loose connections and clamp rings should be checked or replaced if necessary.• Contact Guth South Africa for further assistance.

7.2 Actuator Defects

1 Valve no longer withstands the product pressure.

Causes

• Broken spring(s) when spring closing.• Leaking/torn diaphragm when air closing• Insufficient air pressure when air closing.

Error Correction

• Refer to Multi-Spring Operating Manual further information




2. Faulty valve stroke

Causes

• Leaking or torn diaphragm• Loose SK-nut of the actuator shaft• Actuator shaft obstructed• Valve spindle dragging• Defective air supply• Setpoint value signal faulty or not adjusted• Faulty zero point setting• Faulty spindle setting.

Error Correction

• Refer to valve, multi-spring actuator and DigiPos operating manuals.

3. Jerky stroke motion.

Causes

• Broken spring• Actuator shaft or valve spindle dragging.

Error Correction

• Refer to the relevant operating manuals.

7.3 Positioner defects

Causes

• Insufficient supply air pressure• Faulty set point signal• Faulty position sensor• Faulty electronic circuit board

Error Correction

• Refer to DigiPos operating manual.• Contact Guth South Africa for advice and assistance.




Options

A number of valve options are available got the Guth Stainless Steel modulating / control vavles type VSR depending onthe application.

Standard Angle and In-Line versions




Mixing



Distribution

Pressure Reduction


KVS Data



M02 M1 M2 M3 M4 M9 M10 H1 H2128 74 129

0.8-4.0 0.75-1.5 1.5-3.0 0.7-1.5 1.5-3.0 0.7-1.5 1.4-3.0 2.5-5.0 2.5-5.0

6 3 6 3 6 6 12DN kvs (m!/hr) Seat Ø mm10 0,1 6 16,0 16,015 1,0 7 16,0 16,020 1,6 8,5 16,0 16,0 16,0 16,0

2,5 11 16,0 16,0 16,0 16,0 16,04,0 16 16,0 16,0 16,0 16,0 16,07,0 19 16,0 16,0 16,0 16,0 16,09,0 24 11,0 16,0 16,0 16,0 16,07,0 19 16,0 16,0 16,0 16,0 16,011,0 24 11,0 16,0 16,0 16,0 16,015,0 32 6,0 16,0 16,0 16,0 16,011,0 24 11,0 16,0 16,0 16,0 16,018,0 32 16,0 16,0 16,0 16,018,0 32 12,0 16,0 12,0 16,0 16,0 16,026,0 37 8,4 16,0 8,4 16,0 16,0 16,028,0 48 7,4 16,0 7,7 16,0 9,1 16,026,0 37 8,4 16,0 16,0 16,043,0 48 7,7 16,0 9,1 16,050,0 62 4,4 11,0 5,1 8,943,0 48 7,7 16,0 9,1 16,068,0 62 4,3 11,0 5,1 8,985,0 73 2,0 7,9 3,4 6,468,0 62 4,3 11,0 16,0 16,0 8,9100,0 73 2,9 7,9 16,0 16,0 6,4120,0 90 1,7 5,0 14,0 16,0 3,8150,0 90 10,0 10,0260,0 115 7,8 10,0

150 380,0 135 5,5 8,2

Product PressuresAbove 10 BarUp to 10 Bar

From 1 to 6 Bar

80

100

125

25

32

40

50

65

Number of springs 1

Air pressure range (Bar)Stroke (mm) 20 30 60 25

Actuator Type Membrane Actuators Piston Actuators

Effective area (cm2) 320 720


Mem

bran

e A

ctua

tors

M02

M1

M2

M3

M4

M9

M10

165

270

270

270

270

400

400

9613

913

916

516

523

723

718

722

722

726

026

038

438

497

9797

9797

155

155

M14

M14

M14

M14

M14

M14

M14

2020

2030

3060

6012

832

032

032

032

072

072

06

36

36

612

0.8-

4.0

0.5-

1.5

1.0-

3.0

0.65

-2.2

1.3-

4.4

3.1-

4.6

3.3-

4.3

0,72

1,5

3,1

2,1

4,2

1,9

3,4

Air

load

(kN

), ai

r cl

osin

g4.

5 Ba

r3,

59,

54,

77,

53,

520

,530

,8A

t ai

r pr

essu

re (

Bar)

6.0

Bar

5,4

14,3

9,5

12,2

5,3

10,3

20,6

G (

inte

rnal

thr

ead)

Stro

ke (

mm

)Ef

fect

ive

area

(cm

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umbe

r of

spr

ings

Ope

ratin

g pr

essu

re (

Bar)

(M

ax –

Min

)Sp

ring

load

(kN

)

Type

Me

mb

ran

e A

ctu

ato

rs

D H1

H2

C

Flow

Com

pone

nts

Cap

ital E

quip

men

tEn

gine

ered

Pro

cess

ing

Uni

ts

Pist

on a

nd R

otar

y A

ctua

tors

Air

/ Spr

ing

Air

/ A

irA

ir /

Spri

ngA

ir /

Air

Air

/ Sp

ring

Air

/ A

irA

ir /

Spri

ngA

ir /

Air

102

102

133

133

102

102

133

133

182

182

182

182

182

182

220

220

215

215

215

215

202

202

240

240

Ø76

: 4x

M8

Ø76

: 4x

M8

Ø76

: 4x

M8

Ø76

: 4x

M8

Ø75

: 4x

M8

Ø75

: 4x

M8

Ø75

: 4x

M8

Ø75

: 4x

M8

3030

3030

--

--

2525

2525

--

--

6363

115

115

7070

/62

124

124/

113

0,8

1,6

1,6

3,2

2,6

4,8

59,

61,

9-

3,4

-1,

6-

2,3

-6.

0 Ba

r-

3,2

-6,

2-

--

-4.

5 Ba

r-

2,4

-4,

6-

--

-Sw

itchi

ng t

ime

(sec

) ai

r ag

ains

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air

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spri

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4-

1,6

--

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0,8

-1,

2-

--

--

actu

ator

air

-0,

8-

1-

--

-5

55

55

55

5

Pist

on a

rea

(cm

!)A

ir c

onsu

mpt

ion

(l/do

uble

str

oke)

at

6.0

Bar

Spri

ng lo

ad (

kN)

Air

load

(kN

) at

Air

pre

ssur

e 6

Bar

Req

uire

d m

in a

ir p

ress

ure

(Bar

)

D H1

H2

C d Stro

ke (

mm

)

Type

Pist

on A

ctua

tors

Rot

ary

Act

uato

rsPV

1PV

2PS

2PS

3

Flow

Com

pone

nts

Cap

ital E

quip

men

tEn

gine

ered

Pro

cess

ing

Uni

ts

Mod

ulat

ing

Val

ve T

ype

VSR

-L w

ith D

igiP

os P

ositi

oner

Flow

Com

pone

nts

Cap

ital E

quip

men

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ered

Pro

cess

ing

Uni

ts

Mod

ulat

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Val

ve T

ype

VSR

-LS

with

Dig

iPos

Pos

ition

er

Flow

Com

pone

nts

Cap

ital E

quip

men

tEn

gine

ered

Pro

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Uni

ts

Mod

ulat

ing

Val

ve T

ype

VSR

-L w

ith A

RC

A P

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Flow

Com

pone

nts

Cap

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quip

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Pro

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ing

Uni

ts

Mod

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Val

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VSR

-LS

with

AR

CA

Pos

ition

er

Flow

Com

pone

nts

Cap

ital E

quip

men

tEn

gine

ered

Pro

cess

ing

Uni

ts

Contact Us

Johonnesburg:79 St Georges Street, NewlandsPO Box 58070, Newville, 2114Phone: + 27 (0)11 477-4923Fax: + 27 (0)11 477-8062e-mail: [email protected]

Cape Town:2 Platinum Rd, Marconi Industria, Montague GardensPO Box 1486, Milnerton, 7435Phone: + 27 (0)21 555-8300Fax: + 27 (0)21 552-2228e-mail: [email protected]

Port Elizabeth:Unit 24, Willow Road Business Park, 33 Willow Road, FairviewPO Box 70496, The Bridge PO, Port Elizabeth, 6032Phone: + 27 (0)41 367 2431Fax: + 27 (0)41 367 5152email: [email protected]

Pinetown:Unit 3 Pastel Park, 50 Wareing RoadPO Box 8, Pinetown, 3600Phone: + 27 (0)31 709-5444Fax: + 27 (0)31 709-8333e-mail: [email protected]

operating manual - guthguth.co.za/pdf/m/throttle valves vsr.pdf1 valve design 03 1.1 general...

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