What is a VALVE?

Valve is a device to control the fluid flow by operating the closure member with manual or automatic operation in a piping system.automatic operation in a piping system.

IMPORTANT TOPICS ON VALVE

1. Functions of valve

2. Important Valve parts/terminology

3. Type of valves3. Type of valves

4. Selection of valve type

5. Codes & Standards

6. Material of construction

7. Special requirements

8. Valve specification

1. FUNCTIONS OF VALVE1. FUNCTIONS OF VALVE

Valves shall be used in the following operations in Valves shall be used in the following operations in process piping systems.process piping systems.

Open or Close Open or Close

Flow regulation Flow regulation Flow regulation Flow regulation

Prevent the back flow Prevent the back flow

To change the flow directionTo change the flow direction

To control the PressureTo control the Pressure

To relieve the pressure To relieve the pressure

2. Important Valve parts/terminology2. Important Valve parts/terminology

BodyBody

Bonnet or cover plateBonnet or cover plate

Wedge/ball/plug/discWedge/ball/plug/disc

Seat/seat ringSeat/seat ring

StemStem

Valve trim (wetted, removable and replaceable Valve trim (wetted, removable and replaceable Valve trim (wetted, removable and replaceable Valve trim (wetted, removable and replaceable valve internal part)valve internal part)

YokeYoke

GlandGland

StelliteStellite

Full bore/reduced boreFull bore/reduced bore

Sealing/packingSealing/packing

3. TYPE OF VALVE3. TYPE OF VALVE

Most commonly used valves in process system Most commonly used valves in process system areare

Gate ValveGate Valve Globe ValveGlobe Valve

Check ValveCheck Valve Check ValveCheck Valve Ball ValveBall Valve Butterfly ValveButterfly Valve Plug ValvePlug Valve Control ValveControl Valve Safety ValveSafety Valve

GATE VALVEGATE VALVE

Gate valves are widely used valves in process Gate valves are widely used valves in process

industries.industries.

It is normally used for onIt is normally used for on--off service.off service.

It has a biIt has a bi--directional sealing capacity and there directional sealing capacity and there fore can be installed in the line in either direction.fore can be installed in the line in either direction.

Can be used for the most of the service.Can be used for the most of the service.Can be used for the most of the service.Can be used for the most of the service.

Gate valve has following parts Body, bonnet, Gate valve has following parts Body, bonnet, Wedge (gate), Gland, Stem packing, Trim ( stem, Wedge (gate), Gland, Stem packing, Trim ( stem, body seat ring, gate seat ring), Hand wheel.body seat ring, gate seat ring), Hand wheel.

Types of wedgesTypes of wedges

1. Flexible wedge1. Flexible wedge

The flexible wedge is cast or machined steel with The flexible wedge is cast or machined steel with groove to allow seat ring to move independently groove to allow seat ring to move independently and adjust to movement of body seats. It is used and adjust to movement of body seats. It is used where line load or thermal expansion of the system where line load or thermal expansion of the system is likely to distort the seat.is likely to distort the seat.

2. Solid Wedge2. Solid Wedge

The solid wedge is simplest and most economical of The solid wedge is simplest and most economical of various wedge types. The disadvantage of this various wedge types. The disadvantage of this wedge does not self compensating to seat distortion wedge does not self compensating to seat distortion caused by thermal expansion.caused by thermal expansion.

GATE VALVEGATE VALVE

PARTSPARTS

BODYBODY

BONNETBONNET

GATEGATE

STEMSTEM STEMSTEM

GLANDGLAND

PACKINGPACKING

HAND WHEELHAND WHEEL

AdvantagesAdvantages

1. Good shut off characteristics.1. Good shut off characteristics.

2. Bidirectional use2. Bidirectional use

3. Pressure loss through the valve is minimal.3. Pressure loss through the valve is minimal.

DisadvantagesDisadvantages

1. Not possible for quick opening or closing.1. Not possible for quick opening or closing.1. Not possible for quick opening or closing.1. Not possible for quick opening or closing.

2. Requires large space for installation and 2. Requires large space for installation and maintenance.maintenance.

3. Due to slow movement of closing, the velocity 3. Due to slow movement of closing, the velocity of fluid increases and causes chattering and of fluid increases and causes chattering and damages the seat and other parts.damages the seat and other parts.

4. Not suitable for throttling operation.4. Not suitable for throttling operation.

GLOBE VALVEGLOBE VALVE

Globe valves are widely used valves in process Globe valves are widely used valves in process industries.industries.Globe can be used for throttling as well as onGlobe can be used for throttling as well as on--off off service.service.Can be used for the most of the service.Can be used for the most of the service.Globe valve has following parts Globe valve has following parts Body, Bonnet,Disc,Gland, Stem packing, Trim Body, Bonnet,Disc,Gland, Stem packing, Trim Body, Bonnet,Disc,Gland, Stem packing, Trim Body, Bonnet,Disc,Gland, Stem packing, Trim (stem, body seat, Disc seat), Hand wheel.(stem, body seat, Disc seat), Hand wheel.Globe valve can be used for size up to 8”.Globe valve can be used for size up to 8”.As the diameter become larger disc vibration will As the diameter become larger disc vibration will be high, Since the disc is not supported at be high, Since the disc is not supported at periphery when the valves in open position. periphery when the valves in open position. Guided discs are some time used to avoid Guided discs are some time used to avoid vibration.vibration.

GLOBE VALVEGLOBE VALVE

PARTSPARTS

BODYBODY

BONNETBONNET

DISCDISC

STEMSTEM STEMSTEM

SEATSEAT

BACK SEATBACK SEAT

GLANDGLAND

PACKINGPACKING

HAND WHEELHAND WHEEL

AdvantagesAdvantages

1. Good shut off characteristics.1. Good shut off characteristics.

2. Good for throttling operation.2. Good for throttling operation.

3. Smaller in size compare to gate valve.3. Smaller in size compare to gate valve.

4. shorter stroke compare to gate valve.4. shorter stroke compare to gate valve.

5. Easy of maintenance.5. Easy of maintenance.

DisadvantagesDisadvantages

1. High pressure drop through the valve.1. High pressure drop through the valve.

2. requires greater force to operate the valve.2. requires greater force to operate the valve.

3. Size limitation due to the vibration of stem and 3. Size limitation due to the vibration of stem and disc.disc.

BALL VALVEBALL VALVE

Ball valves are used for tight shut off service.Ball valves are used for tight shut off service.

Soft seat (PTFE) gives tight sealing capacity Soft seat (PTFE) gives tight sealing capacity for ball valve.for ball valve.

It can also be used for quick onIt can also be used for quick on--off service. off service. Soft seated ball valve having limitation on Soft seated ball valve having limitation on service temperature.service temperature.service temperature.service temperature.

It depends on the temperature with standing It depends on the temperature with standing

capacity of soft seatcapacity of soft seat..Ball valve has the following partsBall valve has the following parts

Body, Ball, Stem , seat, Stem seal and Body, Ball, Stem , seat, Stem seal and wrench.wrench.

Types of ball valvesTypes of ball valves

Based on ball typeBased on ball type1. Floating ball valve1. Floating ball valve2. Trunnion mounted ball valve2. Trunnion mounted ball valve

Floating ball valve shall be used for small bore and Floating ball valve shall be used for small bore and low pr valves.low pr valves.In the closed state of floating ball valve, the ball is In the closed state of floating ball valve, the ball is stressed against the soft seat by the upstream stressed against the soft seat by the upstream In the closed state of floating ball valve, the ball is In the closed state of floating ball valve, the ball is stressed against the soft seat by the upstream stressed against the soft seat by the upstream pressure.pressure.This force may cause damage to seat in case of big This force may cause damage to seat in case of big bore and high pr valve.bore and high pr valve.Hence trunnion mounted valves are used for big Hence trunnion mounted valves are used for big bore valves.bore valves.

Based on seatBased on seat

1. Soft seated valve1. Soft seated valve

2. Metal to metal seated valve2. Metal to metal seated valve

Based on body constructionBased on body construction

1. One piece construction (Top entry and end entry)1. One piece construction (Top entry and end entry)

2. Spilt construction (2 piece and 3 piece 2. Spilt construction (2 piece and 3 piece construction)construction)construction)construction)

BALL VALVEBALL VALVE

PARTSPARTS

BODYBODY

BALLBALL

SEATSEAT SEATSEAT

STEMSTEM LEVERLEVER

BALL VALVEBALL VALVE

AdvantagesAdvantages

1. Provides bubble tight shut off.1. Provides bubble tight shut off.

2. Quick open or quick close is possible.2. Quick open or quick close is possible.

3. Smaller in size compare to gate valve.3. Smaller in size compare to gate valve.

4. Lighter in weight.4. Lighter in weight.

5. Multi port design is possible and hence number of 5. Multi port design is possible and hence number of valves can be reduced.valves can be reduced.

6. Several design are available for flexibility of 6. Several design are available for flexibility of 6. Several design are available for flexibility of 6. Several design are available for flexibility of selection ofselection of valve.valve.

7. Can be used in clean & slurry applications.7. Can be used in clean & slurry applications.

DisadvantagesDisadvantages

1. Pressure drop through the valve will occur in 1. Pressure drop through the valve will occur in reduced bore valves.reduced bore valves.

2. Not suitable for sustained throttling operation.2. Not suitable for sustained throttling operation.

3. In slurry or other application, the suspended 3. In slurry or other application, the suspended particles can settle become trapped in body particles can settle become trapped in body cavities causing wear, leakage and valve cavities causing wear, leakage and valve failure.failure.failure.failure.

4. Costlier compare to gate valve.4. Costlier compare to gate valve.

5. Site maintenance is not possible as the valves 5. Site maintenance is not possible as the valves having the precision components having the precision components

CHECK VALVECHECK VALVE

Check valve are unidirectional.Check valve are unidirectional.

It open automatically by fluid pressure and close It open automatically by fluid pressure and close when flow reverse or stop.when flow reverse or stop.

Types of check valvesTypes of check valvesTypes of check valvesTypes of check valves

Large number of check valve type are available.Large number of check valve type are available.

Swing check valve, Lift check valve, Dual plate Swing check valve, Lift check valve, Dual plate check valve and wafer type valve.check valve and wafer type valve.

CHECK VALVECHECK VALVE

PARTSPARTS

BODY BODY

DISCDISC

COVER PLATECOVER PLATE

HINGEHINGE HINGEHINGE

HINGE PINHINGE PIN

SPRINGSPRING

SEAT RINGSEAT RING

BUTTERFLY VALVEBUTTERFLY VALVE

Butterfly valves shall be used for flow regulation Butterfly valves shall be used for flow regulation service in big bore lines.service in big bore lines.

It shall not be used for high pressure serviceIt shall not be used for high pressure service..

It is simple in construction.It is simple in construction.

Quick close and open is possible.Quick close and open is possible. Quick close and open is possible.Quick close and open is possible.

Type of valvesType of valves

Wafer typeWafer type

Lug typeLug type

Flanged valvesFlanged valves

BUTTERFLY VALVEBUTTERFLY VALVE

PARTSPARTS

BODYBODY

DISCDISC

SEATSEAT SEATSEAT

STEMSTEM

HANDLEHANDLE

BUTTERFLY VALVEBUTTERFLY VALVE

AdvantagesAdvantages

1. The compact design requires less space than 1. The compact design requires less space than any other any other valves.valves.

2. Light in weight.2. Light in weight.

3. Provides bubble tight shut off.3. Provides bubble tight shut off.

4. Quick open or close.4. Quick open or close.4. Quick open or close.4. Quick open or close.

5. Easy of maintenance.5. Easy of maintenance.

6. Available in larger size.6. Available in larger size.

BUTTERFLY VALVEBUTTERFLY VALVE

DisadvantagesDisadvantages

1. Throttling is possible for low differential 1. Throttling is possible for low differential pressure.pressure.

2. Unguided disc will affected in the turbulence 2. Unguided disc will affected in the turbulence flow.flow.flow.flow.

3. Location of valve, pipe routing, free and closed 3. Location of valve, pipe routing, free and closed discharge are discharge are to be considered while using to be considered while using a butterfly valve in throttlinga butterfly valve in throttling application.application.

4. Selection of valve type4. Selection of valve type

The following basic factors determine the selection The following basic factors determine the selection of valveof valve

4.1 Function4.1 Function4.2 Service condition4.2 Service condition4.3 Safety considerations4.3 Safety considerations4.3 Safety considerations4.3 Safety considerations4.4 Weight & size limitations4.4 Weight & size limitations4.5 Sealing requirement4.5 Sealing requirement4.6 Cost & availability4.6 Cost & availability4.7 Operability & maintenance4.7 Operability & maintenance4.8 Standard valve design4.8 Standard valve design

4.1 Function4.1 Function

As we have discussed in the Topic As we have discussed in the Topic --1, Different type of 1, Different type of Valves are available for several functions.Valves are available for several functions.

Valve shall be selected based on the function required in the Valve shall be selected based on the function required in the piping system. For examplepiping system. For example

Open or Close Open or Close –– Eg. Gate valve, Diaphragm valve.Eg. Gate valve, Diaphragm valve.

Flow control (Throttling) Flow control (Throttling) –– Eg. Globe valve, plug valveEg. Globe valve, plug valve

Prevent the back flow (NRV) Prevent the back flow (NRV) –– Eg. Check valveEg. Check valve

For your reference please refer the table for valve selection For your reference please refer the table for valve selection based on the operation.based on the operation.

4.2 Service condition4.2 Service condition

Valve selection and material of construction is Valve selection and material of construction is based on the process fluid properties.based on the process fluid properties.

Pressure & temperature of the process fluid also Pressure & temperature of the process fluid also defines the material of construction and design of defines the material of construction and design of valve valve

Valves on the Sour service (wet hyd. Sulphide) Valves on the Sour service (wet hyd. Sulphide) Valves on the Sour service (wet hyd. Sulphide) Valves on the Sour service (wet hyd. Sulphide) may comply with the requirements of NACE MR may comply with the requirements of NACE MR 01750175

Valves in cryogenic service requires special Valves in cryogenic service requires special construction (Refer BS 6364).construction (Refer BS 6364).

Valves in oxygen service requires special care in Valves in oxygen service requires special care in construction and dust free.construction and dust free.

4.3 Safety considerations4.3 Safety considerations

Fire Safe designFire Safe design

Fire safe design applies for the soft seated valves. It Fire safe design applies for the soft seated valves. It is a test to check the sealing capability of valve in is a test to check the sealing capability of valve in the fire atmosphere.the fire atmosphere.

It is a destructive testing and normally conducted in It is a destructive testing and normally conducted in the design stage of valve.the design stage of valve.

Valves are usually the first line of control in the Valves are usually the first line of control in the flammable system requires the fire safe design.flammable system requires the fire safe design.

The applicable codes for fire test is API 607, API 6FA The applicable codes for fire test is API 607, API 6FA & BS 6755 Part II.& BS 6755 Part II.

Locking systemLocking system

For process requirements valve can be locked For process requirements valve can be locked with a pad lock or chain lock. A particular with a pad lock or chain lock. A particular operator can operate the valve.operator can operate the valve.

Antistatic designAntistatic design

Normally all metallic piping system is bonded and Normally all metallic piping system is bonded and earthed for continuity and discharge for the static earthed for continuity and discharge for the static charge produced in some of the process piping charge produced in some of the process piping system.system.

For valves having sealing of non metallic material For valves having sealing of non metallic material For valves having sealing of non metallic material For valves having sealing of non metallic material will cause a damage to seat and seal by the static will cause a damage to seat and seal by the static charge. Also this will affect the operator by means of charge. Also this will affect the operator by means of shock or burns.shock or burns.

The static charge produced in the stem/ball can be The static charge produced in the stem/ball can be transferred to the body of the valve by means of transferred to the body of the valve by means of metallic bush. This design is called antistatic design.metallic bush. This design is called antistatic design.

Fully welded designFully welded design

Some times valve requires welded construction in case of Some times valve requires welded construction in case of highly toxic and carcinogenic fluid service to avoid the leakage highly toxic and carcinogenic fluid service to avoid the leakage and accidents.and accidents.

Large diameter valves in the pipe lines may be used as welded Large diameter valves in the pipe lines may be used as welded valves to reduce the weight.valves to reduce the weight.

Special cleaning requirementsSpecial cleaning requirements

Special cleaning required for the valves in Oxygen, Special cleaning required for the valves in Oxygen, dry chlorine gas & clean processes.dry chlorine gas & clean processes.

Grease or oil or dirt in an oxygen service can Grease or oil or dirt in an oxygen service can generate combustion or ignition in the line.generate combustion or ignition in the line.

water particles left out in the dry chlorine gas water particles left out in the dry chlorine gas system can cause severe corrosion.system can cause severe corrosion.

Valves should be clean for pharmaceutical and Valves should be clean for pharmaceutical and food industry to avoid contamination in product.food industry to avoid contamination in product.

4.4 Weight & size limitations4.4 Weight & size limitations

Size and weight of the valve play an important role Size and weight of the valve play an important role in the selection of valve.in the selection of valve.

Gate and globe valves are too heavy when compare Gate and globe valves are too heavy when compare to ball, plug and butterfly valve.to ball, plug and butterfly valve.

Due to the increased weight, the valve cost will Due to the increased weight, the valve cost will increase and the support on the line will require increase and the support on the line will require increase and the support on the line will require increase and the support on the line will require complicated design.complicated design.

For exampleFor example

Wafer type butterfly valve and wafer check Wafer type butterfly valve and wafer check valves reduces the valve weight and space valves reduces the valve weight and space requirements.requirements.

Butt welded end valves also considerably reduces Butt welded end valves also considerably reduces the space and valve weight.the space and valve weight.

Coupling/clamp type connection can also be used Coupling/clamp type connection can also be used Coupling/clamp type connection can also be used Coupling/clamp type connection can also be used to reduce the valve weight.to reduce the valve weight.

4.5 Sealing requirement4.5 Sealing requirement

Soft seated valvesSoft seated valves

Valves with polymer or elastomeric material seat Valves with polymer or elastomeric material seat and packing can provide a bubble tight shut off. and packing can provide a bubble tight shut off. It is not easy to achieve the bubble tight shut off It is not easy to achieve the bubble tight shut off It is not easy to achieve the bubble tight shut off It is not easy to achieve the bubble tight shut off in the metal seated valves.in the metal seated valves.

Metal to metal seated valvesMetal to metal seated valves

Valves with metal seat can be used for very high Valves with metal seat can be used for very high temperature or very low temperature where the temperature or very low temperature where the non metallic seat materials are not possible. In non metallic seat materials are not possible. In this case the valve is not possible to provide a this case the valve is not possible to provide a bubble tight shut off. How ever these valves are bubble tight shut off. How ever these valves are used with allowable leakage which is mentioned used with allowable leakage which is mentioned used with allowable leakage which is mentioned used with allowable leakage which is mentioned in the API 598 / BS 6755 part 1/ EN 12266.in the API 598 / BS 6755 part 1/ EN 12266.

Stem packingStem packing

For fire safe valve design, a metallic sealing should For fire safe valve design, a metallic sealing should be provided in addition to the soft sealing be provided in addition to the soft sealing material.material.

Valves in full vacuum service special type of Valves in full vacuum service special type of Valves in full vacuum service special type of Valves in full vacuum service special type of packing in order to with stand the vacuum packing in order to with stand the vacuum pressure.pressure.

Pure graphite packing shall be avoided in the Pure graphite packing shall be avoided in the vapour service.vapour service.

4.6 Cost & availability4.6 Cost & availability

The cost and availability of valves shall be taken The cost and availability of valves shall be taken care during the selection of valves.care during the selection of valves.

Selection of valves based on international standards Selection of valves based on international standards and most commonly used material will be and most commonly used material will be and most commonly used material will be and most commonly used material will be economical and readily available in the market.economical and readily available in the market.

Valves with special purpose or manufactured with Valves with special purpose or manufactured with exotic material will be costlier and increase the exotic material will be costlier and increase the delivery period.delivery period.

Also valve cost comparison to be taken care Also valve cost comparison to be taken care during the selection of valve. For example, gate during the selection of valve. For example, gate and globe valves are widely used cheapest valves and globe valves are widely used cheapest valves when compare to ball & plug valveswhen compare to ball & plug valves

Valve data sheet to be prepared based on the Valve data sheet to be prepared based on the specific requirement of piping material specific requirement of piping material specification. The additional testing requirement specification. The additional testing requirement specification. The additional testing requirement specification. The additional testing requirement inspection requirement will cause an cost impact inspection requirement will cause an cost impact and prolonged delivery period.and prolonged delivery period.

4.7 Operability & maintenance4.7 Operability & maintenance

Valve selection is also based on the operability and Valve selection is also based on the operability and maintenance.maintenance.

Butt welded valves gives high integrity, low leak Butt welded valves gives high integrity, low leak proof but not recommended for periodical proof but not recommended for periodical maintenance.maintenance.

Ball valves & plug valves are having more precision Ball valves & plug valves are having more precision components when compare to gate & globe valves. It components when compare to gate & globe valves. It is not advisable to carry over the maintenance in the is not advisable to carry over the maintenance in the site due to dirty atmosphere.site due to dirty atmosphere.

Spares to be maintained at the stores for at least 2 Spares to be maintained at the stores for at least 2 years. years.

4.8 Standard valve design4.8 Standard valve design

For ½”For ½”--1 ½” valves end connection shall be 1 ½” valves end connection shall be selected as socket welded or screwed based on selected as socket welded or screwed based on the piping specification. For soft seated valves, the piping specification. For soft seated valves, the end connection may be flanged or the valve the end connection may be flanged or the valve welded with pipe nipples will be available in the welded with pipe nipples will be available in the market.market.market.market.

For 2” & above valves shall be easily available for For 2” & above valves shall be easily available for flanged end (FF/RF) for 150#, 300# & 600#.flanged end (FF/RF) for 150#, 300# & 600#.

Valves with RTJ flanged end shall be selected for Valves with RTJ flanged end shall be selected for 900# and above.900# and above.

Butt welded or hub type end connection valves Butt welded or hub type end connection valves may be selected for high pressure valves. may be selected for high pressure valves. (2500#)(2500#)

The operator of the valve shall be selected based The operator of the valve shall be selected based on the availability.on the availability.

Wrench/lever/TWrench/lever/T--bar operator shall be selected for bar operator shall be selected for quarter turn valves.quarter turn valves.

Hand wheel shall be selected for multi turn Hand wheel shall be selected for multi turn valves.valves.

Gear operator shall be selected for higher size Gear operator shall be selected for higher size valves where the force required to close or open valves where the force required to close or open valves where the force required to close or open valves where the force required to close or open the valve exceeds 400N.the valve exceeds 400N.

Chain operator may be selected based on the Chain operator may be selected based on the operability of valve.operability of valve.

5. Codes & standards5. Codes & standards

Some of the international codes & standards are given below Some of the international codes & standards are given below for the valves design and dimensions.for the valves design and dimensions.

ASME B16.10ASME B16.10 –– Face to face & end to end dimensions of Face to face & end to end dimensions of flanged and butt welded valves.flanged and butt welded valves.

ASME B16.34ASME B16.34 –– Valve Valve –– flanged, threaded and welded ends. flanged, threaded and welded ends. ASME B16.34ASME B16.34 –– Valve Valve –– flanged, threaded and welded ends. flanged, threaded and welded ends. (Covers the wall thickness, P & T rating and design)(Covers the wall thickness, P & T rating and design)

API 598API 598 –– Valve inspection and testing.Valve inspection and testing.

API 607API 607 –– Fire test for soft seated quarter turn valves.Fire test for soft seated quarter turn valves.

API 6FAAPI 6FA –– Fire test for valvesFire test for valves

API Standard 594API Standard 594 Check ValvesCheck Valves

API Standard 599API Standard 599 Metal Plug ValvesMetal Plug Valves

API Standard 600API Standard 600 Bolted Bonnet Steel Gate Valves Bolted Bonnet Steel Gate Valves -- Bolted Bolted Bonnet Steel Gate ValvesBonnet Steel Gate Valves

API Standard 602API Standard 602 Compact Steel Gate Valves, Globe Valves Compact Steel Gate Valves, Globe Valves and Check Valvesand Check Valves

API Standard 608API Standard 608 Metal Ball ValvesMetal Ball Valves

API Standard 609API Standard 609 Butterfly ValvesButterfly Valves

API Spec 6DAPI Spec 6D Pipeline Valves (Steel Gate, Plug, Ball, and Pipeline Valves (Steel Gate, Plug, Ball, and Check Valves) Check Valves) –– Gate Valves; Plug Valves; Ball Valves; Check Gate Valves; Plug Valves; Ball Valves; Check Check Valves) Check Valves) –– Gate Valves; Plug Valves; Ball Valves; Check Gate Valves; Plug Valves; Ball Valves; Check Valves Valves

BS EN 17292BS EN 17292 –– Metal Ball Valves (This International Metal Ball Valves (This International Standard supersedes BS 5351)Standard supersedes BS 5351)

BS 5353BS 5353 -- Steel plug valvesSteel plug valves

BS 6364BS 6364 -- Valves for cryogenic serviceValves for cryogenic service

BS 1873BS 1873 -- Globe valvesGlobe valves

6. CONSTRUCTION & DESIGN OF VALVE6. CONSTRUCTION & DESIGN OF VALVE

Material for process wetted parts of valve shall be Material for process wetted parts of valve shall be suitable for service fluid. ASTM specification for suitable for service fluid. ASTM specification for various material used for valve body material are various material used for valve body material are as follow.as follow.

CABON STEELCABON STEEL

A 105A 105

A 216 Gr WCBA 216 Gr WCB

LOW TEMP CARBON STEELLOW TEMP CARBON STEEL

A 350 GrLF2A 350 GrLF2

A352 Gr LCC/ LCBA352 Gr LCC/ LCB

STAINLESS STEELSTAINLESS STEEL

A 182 Gr 316/ 304A 182 Gr 316/ 304

A 351 Gr CF8M / CF8A 351 Gr CF8M / CF8

ALLOY STEEL 1.25 CrALLOY STEEL 1.25 Cr--0.5 Mo0.5 Mo

-- A 182 Gr F11 cl 2A 182 Gr F11 cl 2

-- A 217 Gr WC6A 217 Gr WC6

ALLOY STEEL 2.25 CrALLOY STEEL 2.25 Cr--1 Mo1 Mo

--A182 Gr F22 cl 3A182 Gr F22 cl 3

--A217 Gr WC9A217 Gr WC9

TRIMTRIM

The most commonly used trim are The most commonly used trim are

13 Cr 13 Cr -- 182 F6a / A 217 CA 15182 F6a / A 217 CA 15

HARDFACED HARDFACED -- STELLITE STELLITE

13 Cr & HARDFACED 13 Cr & HARDFACED -- A182 F6a & STELLITE A182 F6a & STELLITE

18Cr 18Cr –– 8 Ni (SS 316)8 Ni (SS 316)-- A 182 F316A 182 F316 18Cr 18Cr –– 8 Ni (SS 316)8 Ni (SS 316)-- A 182 F316A 182 F316

DESIGN STANDARDSDESIGN STANDARDS

Valves shall be designed according to Valves shall be designed according to ASME ASME B16.34B16.34 . Class rating (pressure temperature . Class rating (pressure temperature rating) of valve shall be selected according to this rating) of valve shall be selected according to this standard. Design temperature and pressure of standard. Design temperature and pressure of valve should be with in the limit of pressure valve should be with in the limit of pressure --valve should be with in the limit of pressure valve should be with in the limit of pressure --temp curve of concern class rating.temp curve of concern class rating.

For exampleFor example

Gate valve, A 105, design temp 100 deg F Gate valve, A 105, design temp 100 deg F

design pressure design pressure -- 200 psig 200 psig

Class rating shall be 150 lbsClass rating shall be 150 lbs

Temp F -20 100 200 300 400 500 600 650 700 750 800 850 900 950 1000

pressure (psig) 285 285 260 230 200 170 140 125 110 95 80 65 50 35 20

PPRESSURE TEMP CURVE FOR CS 150 CLASS RATING ASME B16.34A 105, A 216 WCB, A 515 70

class 150

300

0

50

100

150

200

250

300

-20

10

0

20

0

30

0

40

0

50

0

60

0

65

0

70

0

75

0

80

0

85

0

90

0

95

0

10

00

Temperature in F

Wo

rkin

g p

ressu

re (

psig

)

class 150

In addition to ASME B 16.34 the requirement of In addition to ASME B 16.34 the requirement of all the standards mentioned in the topic 2.8 all the standards mentioned in the topic 2.8 shall be complied as applicableshall be complied as applicable

DIMENSION STANDARDSDIMENSION STANDARDS

FACE TO FACE FACE TO FACE

Face to face and end to end dimension of valves Face to face and end to end dimension of valves shall be according to shall be according to ASME B 16.10ASME B 16.10

VALVE END VALVE END

Valve end dimensions shall be acc. To the following Valve end dimensions shall be acc. To the following Valve end dimensions shall be acc. To the following Valve end dimensions shall be acc. To the following standards as applicablestandards as applicable

FLANGED END ASME B 16.5FLANGED END ASME B 16.5

SOCKET WELDED END ASME B 16.11SOCKET WELDED END ASME B 16.11

SCREWED END ASME B 16.11SCREWED END ASME B 16.11

BUTT WELDED END ASME B16.25BUTT WELDED END ASME B16.25

VALVE OPERATORVALVE OPERATOR

HAND WHEEL OPERATEDHAND WHEEL OPERATED

-- Shall be used for small bore valvesShall be used for small bore valves

GEAR OPERATEDGEAR OPERATED

-- Shall be used for big bore valves. Gear operated valve Shall be used for big bore valves. Gear operated valve shall be provided for the following size range acc. to shall be provided for the following size range acc. to shall be provided for the following size range acc. to shall be provided for the following size range acc. to TP std.TP std.

Type of valve Rating Diameter

Gate Valve 150 / 300 lbs 14 " and over

600 lbs 12 "and over

900 lbs 8" and over

1500 / 2500 lbs 6" and over

Globe valve 150 / 300 lbs 8" and over

600 / 900lbs 6" and over

1500 / 2500 lbs 4" and over

VALVE OPERATORVALVE OPERATOR

When specified power operator has to be provided When specified power operator has to be provided (motor / Pneumatic operated)(motor / Pneumatic operated)

7. SPECIAL REQUIREMENT7. SPECIAL REQUIREMENT

HIGH PR. STEAM SERVICEHIGH PR. STEAM SERVICE

Valve shall be provided with pressure seal bonnet and seat Valve shall be provided with pressure seal bonnet and seat shall be hard faced.shall be hard faced.

CRYOGENIC SERVICECRYOGENIC SERVICE

Valves shall be made entirely of SS material and shall be Valves shall be made entirely of SS material and shall be provided with extended bonnet so that temp at packing provided with extended bonnet so that temp at packing provided with extended bonnet so that temp at packing provided with extended bonnet so that temp at packing should be near atm. should be near atm.

SOUR SERVICESOUR SERVICE

Valve material used in sour service shall meet the Valve material used in sour service shall meet the requirement of NACE MR 01 75requirement of NACE MR 01 75

VOLATILE AND TOXICVOLATILE AND TOXIC

Valves shall be provide with bellow seal.Valves shall be provide with bellow seal.

FIRE SAFE DESIGNFIRE SAFE DESIGN

Soft seat shall be backed by steel ring so that in case of fire Soft seat shall be backed by steel ring so that in case of fire steel ring can seal the fluid.steel ring can seal the fluid.

8. VALVE SPECIFICATION8. VALVE SPECIFICATION

To specify the valve at least the following To specify the valve at least the following parameters has to be definedparameters has to be defined

Valve type : Gate / Globe / Ball ...Valve type : Gate / Globe / Ball ...

Valve size :Diameter Valve size :Diameter

Pressure rating: 150#, 300 #...Pressure rating: 150#, 300 #...

Material of body and trim : ASTM spec...Material of body and trim : ASTM spec...

Material for packing: Graphite ...Material for packing: Graphite ...

Design std : ASME B 16.34, API 600, ...Design std : ASME B 16.34, API 600, ...

Type of bonnet: Welded, Bolted, Pressure sealType of bonnet: Welded, Bolted, Pressure seal

Vale operator: Hand wheel, Gear operatorVale operator: Hand wheel, Gear operator

Valve end type : SW, FE,Screwed End, ..Valve end type : SW, FE,Screwed End, ..

Special requirement:NACE, Fire safe..Special requirement:NACE, Fire safe..

EXAMPLEEXAMPLE

Valve type : GATE VALVEValve type : GATE VALVE

Valve size : 6 “Valve size : 6 “

Pressure rating: 150#Pressure rating: 150#

Material of body and trim : Material of body and trim : BODYBODY A 105 & A 105 & TRIM TRIM Material of body and trim : Material of body and trim : BODYBODY A 105 & A 105 & TRIM TRIM

SS316SS316

Material for packing: GraphiteMaterial for packing: Graphite

Design std : ASME B 16.34Design std : ASME B 16.34

Type of bonnet: BOLTEDType of bonnet: BOLTED

Vale operator: HAND WHEEL OPERATEDVale operator: HAND WHEEL OPERATED

Valve end type : FLANGED END RF acc . ASME B 16.5Valve end type : FLANGED END RF acc . ASME B 16.5

Special requirement:Special requirement:------