presentation of mechanical valve

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12/6/2012

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PRESENTATION ON MECHANICALPRESENTATION ON MECHANICALVALVESVALVES

BYBY ALOK KUMAR SINGHALOK KUMAR SINGH

PURPOSE OF USING VALVES

ValvesValves areare usedused toto controlcontrol thethe flowflow of of liquids,liquids,solidssolids andand gasesgases inin industrialindustrial asas wellwell asas domesticdomesticsituationssituations andand areare oneone of of thethe majormajor pipingpipingcomponentscomponents..

TheThe mostmost commoncommon andand familiarfamiliar valvesvalves areare thethetapstaps usedused inin thethe homehome toto controlcontrol thethe flowflow of of hothotandand coldcold waterwater.. InIn thethe oiloil industry,industry, valvesvalves areare aamajormajor elementelement inin thethe controlcontrol of of operationsoperations..AboutAbout 88--1010%% of of thethe totaltotal capitalcapital expenditureexpenditure of of thethe chemicalchemical industryindustry isis usedused forfor procurementprocurement of of valvesvalves..

VALVES ARE USED FOR ONE OR MORE OF

THREE MAIN PURPOSES

To control the rate of flowTo control the rate of flow

(throttle);(throttle);

To shut off/permit flow (ON/OFFTo shut off/permit flow (ON/OFF

function);function);To isolate systems and protectTo isolate systems and protect

productsproducts..

VALVE CLASSIFICATION BASED ONVALVE CLASSIFICATION BASED ON

FUNCTIONFUNCTION

VALVES

ON/OFF REGULATION

GATE

BALL

GLOBE

NEEDLE

NON-RETURN

CHECK

SPECIAL

MULTI-PORT

FLUSHBOTTOM

PLUG

PISTON

DIAPHRAGM

BUTTERFLY

PINCH VALVE

BUTTERFLY

DIAPHRAGM

PISTON

PINCH

FLOAT

FOOT

LINE BLIND


END CONNECTIONSEND CONNECTIONS

VALVES

SCREWD

ENDS

SOCKET

WELD ENDS

FLANGED

ENDS

BUTT

WELD ENDS

SOCKETTED

ENDS

WAFER

TYPE ENDS


MATERIAL OF CONSTRUCTIONMATERIAL OF CONSTRUCTION

VALVES

CASTIRON

BRONZESPECI ALALLOY

GUNMETAL

CARBONSTEEL

SSALLOY

CARBONSTEEL

POLYPROPY--LENE



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STANDARDS OF MANUFACTURESTANDARDS OF MANUFACTURE

Metric/Imperial dimensions;Metric/Imperial dimensions;

British StandardsBritish Standards -- BSBS

German StandardsGerman Standards -- DIN;DIN;

US StandardsUS Standards -- ANSI (previously ASA);ANSI (previously ASA);

American Petroleum InstitutionAmerican Petroleum Institution -- API. (flangesAPI. (flangesand other equipment are commonly used in the oiland other equipment are commonly used in the oilindustryindustryValvesValves areare ratedrated accordingaccording toto thethe maximummaximumpressurepressure andand temperaturetemperature atat whichwhich theythey cancan safelysafelybebe usedused..

Some API standard are :Some API standard are :

API 6DAPI 6D-- Pipe Line ValvePipe Line Valve

API 600API 600 –– Steel Gate ValveSteel Gate Valve

API 602API 602-- Carbon Steel Gate ValvesCarbon Steel Gate Valves

API 609API 609-- Butterfly ValvesButterfly Valves

Some BS standard are :Some BS standard are :

BS 1414BS 1414-- Gate Valve For Petroleum IndustryGate Valve For Petroleum Industry

BS 1868BS 1868-- Steel Check Valve For Petroleum IndustrySteel Check Valve For Petroleum Industry

BS 1673BS 1673-- Steel Globe Valve For Petroleum IndustrySteel Globe Valve For Petroleum Industry

BS 5155BS 5155-- Butterfly ValveButterfly Valve

BS 5351BS 5351-- Steel Ball ValveSteel Ball Valve

BS 5353BS 5353-- Carbon Steel And Alloy Steel Plug ValveCarbon Steel And Alloy Steel Plug Valve

VALVE TYPE SELECTION CRITERIA

Size limitations

Cost

,

pressure and flow rate

ServiceMaintenance requirements

VALVE STROKE(OPENNESS) VS THE

FLOW

Equal Percentage: equal increments of equal increments of valve travel produce an equal percentage invalve travel produce an equal percentage in

flowflow changechange

vave rave s rec y propor onavave rave s rec y propor ona

to the valve stoketo the valve stoke

Quick opening: large increase in flow withlarge increase in flow witha small change in valve strokea small change in valve stroke

Curve A = Quick Opening

VALVE CHARACTERISTICS

EQUAL-PERCENTAGE VALVE

LINEAR VALVE.

QUICK-OPENING VALVE.

Curve B = Linear

Curve C = Equal %

Equal Percentage (most commonly used valve control)Equal Percentage (most commonly used valve control)

Used in processes where large changes in pressure drop areUsed in processes where large changes in pressure drop are

expectedexpected

Used in processes where a small percentage of the totalUsed in processes where a small percentage of the totalpressure drop is permitted by the valvepressure drop is permitted by the valve

Used in temperature and pressure control loopsUsed in temperature and pressure control loops

LinearLinear

Used in liquid level or flow loopsUsed in liquid level or flow loops

Used in systems where the pressure drop across the valve isUsed in systems where the pressure drop across the valve is

expected to remain fairly constant (ie. steady state systems)expected to remain fairly constant (ie. steady state systems)

Quick OpeningQuick Opening

Used for frequent onUsed for frequent on--off serviceoff service

Used for processes where "instantly" large flow is neededUsed for processes where "instantly" large flow is needed

(ie.(ie. safety systems or cooling water systems)safety systems or cooling water systems)



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GATE VALVESGATE VALVESUsed when a tight shutUsed when a tight shut--off is required & there must beoff is required & there must bestraightstraight--line flow of fluid with min. resistanceline flow of fluid with min. resistance

Quick Opening valveQuick Opening valve

Infrequent operationInfrequent operation

Gate usually wedgeGate usually wedge--shaped or a vertical disc as in theshaped or a vertical disc as in thediagramdiagram

A lication: Oil as air slurries heav li uids steam noA lication: Oil as air slurries heav li uids steam no, , , , , ,, , , , , ,condensing gases, and corrosive liquidscondensing gases, and corrosive liquids

AdvAdv: high capacity,No flow restrictions & low cost: high capacity,No flow restrictions & low cost

DisadvDisadv::Poor throttlingPoor throttling

Cavitate at low pressure dropsCavitate at low pressure drops

Gate valves should not be used where frequent operation isGate valves should not be used where frequent operation is

requiredrequired

GATE VALVE

GATE OR DISCGATE OR DISC

BALL VALVEBALL VALVE

To provide a quick opening, linear & simple shutTo provide a quick opening, linear & simple shut--off off

For Fully open/closed, limitedFor Fully open/closed, limited--throttlingthrottling

Higher temperature fluidsHigher temperature fluids

Ball has opening through centre. when this opening is in line with the inlet &Ball has opening through centre. when this opening is in line with the inlet &outlet ports, flow will be allowed.when ball is turned through 90 deg. No flowoutlet ports, flow will be allowed.when ball is turned through 90 deg. No flowcan takes placecan takes place

Application: Normally found in seawater, sanitary, trim and drain, slurry andApplication: Normally found in seawater, sanitary, trim and drain, slurry andhydraulic systemshydraulic systems

AdvAdv::

OOffer minimum resistance to flow

Tight sealing with low torque

Low cost & High capacity

Low leakage and maintenanceOperation, reliability, durability, and capability of withstanding highpressures

DisadvDisadv::

Prone to cavitationsProne to cavitations

Not Suitable For Lines Subject To Pulasting FlowNot Suitable For Lines Subject To Pulasting Flow

Poor throttling characteristicsPoor throttling characteristics

ExpensiveExpensive

BALL VALVEBALL VALVE

BALLBALL

PLUG VALVEPLUG VALVE

To provide a quick, simple shutTo provide a quick, simple shut--off off

Not Common In Sizes Over 6 InchNot Common In Sizes Over 6 InchNot Suitable For Lines Subject To Pulasting FlowNot Suitable For Lines Subject To Pulasting Flow

Controls flow using a plug with a hole through it. PlugsControls flow using a plug with a hole through it. Plugs

can be made of rigid materials such as Tefloncan be made of rigid materials such as Teflon¨̈, making, making

t em ea or gt em ea or g --pur typur ty

AdvAdv::

Good for high pressure applicationsGood for high pressure applications

Easy to operate

Provide a tight shutoff

DisadvDisadv

Plugs may freeze if not operated for a long period

of time

PLUG VALVE



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DIAPHRAGM VALVE

For Low Pressure Corrosive Service As ShutFor Low Pressure Corrosive Service As Shut--off Valvesoff Valves

Diaphragm moves up and down to operate the valveDiaphragm moves up and down to operate the valve

Diaphragm materials available in Nitrile, Hypalon, Neoprene,Diaphragm materials available in Nitrile, Hypalon, Neoprene,PTFE, etc.PTFE, etc.

Application : Slurry Services, Suspended ParticlesApplication : Slurry Services, Suspended Particles (Elastomeric(ElastomericDiaphragm only)Diaphragm only) && Severe ChemicalSevere Chemical

A vA v::

Can Be Used Where Leakage Cannot Be ToleratedCan Be Used Where Leakage Cannot Be Tolerated

Disadv:Disadv:

Can Only Withstand A Maximum Operating Pressure 7 to 10Can Only Withstand A Maximum Operating Pressure 7 to 10Kg/CmKg/Cm22 gg

Require frequent maintenance as damage to diaphragmRequire frequent maintenance as damage to diaphragmoccuroccur

Cannot Withstand Temperature Above 400 Deg FCannot Withstand Temperature Above 400 Deg F

DIAPHRAGM VALVEDIAPHRAGM VALVE

Hand wheelHand wheelVisual I ndicatorVisual I ndicatorTravel StopTravel Stop

BonnetBonnet

DiaphragmDiaphragm

Compressor Compressor

Panel MountPanel MountProvisionProvision

One PieceOne Piece

Molded FlangeMolded Flange

GLOBE VALVES

Throttling service/flow regulation valveThrottling service/flow regulation valve

Linear and Equal percentage valveLinear and Equal percentage valve

Frequent operationFrequent operation

Application: steam, air, water, oil lines, corrosiveApplication: steam, air, water, oil lines, corrosivesubstances & slurriessubstances & slurries

Disc attached to valve stem rests against seat to shut off Disc attached to valve stem rests against seat to shut off flow of fluidflow of fluid

AdvAdv::

Efficient throttling & Accurate flow controlEfficient throttling & Accurate flow control

Available in multiple portsAvailable in multiple ports

DisadvDisadv::

flow resistanceflow resistance

High pressure dropHigh pressure drop

More expensive than other valvesMore expensive than other valves

GLOBE VALVE

NEEDLE VALVE

Most accurate flow control among the valvesMost accurate flow control among the valves

Similar To Globe Valve Except Disc Is Pointed At EndSimilar To Globe Valve Except Disc Is Pointed At End.Steel Valves Are Often Made From Bars stock Arc.Steel Valves Are Often Made From Bars stock ArcRugged.Rugged.

Valves 2 Inch. And Smaller For Use On Pilot Plants And Valves 2 Inch. And Smaller For Use On Pilot Plants AndBench Scale Equipment And Instrument Service .Bench Scale Equipment And Instrument Service .

Good For Manual Flow Control .GroundGood For Manual Flow Control .GroundJoint UnionJoint UnionBonnet Connection Preferable.Bonnet Connection Preferable.

Disadv:Disadv:

Positive ShutPositive Shut – –Off Not Always Posible OrOff Not Always Posible OrDesrible.Desrible.In some designs, seat is scored If ShutIn some designs, seat is scored If ShutDown TightlyDown Tightly

NEEDLE VALVE



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BUTTERFLY VALVESLinear, Equal percentage & & Positive shut –off quarter turn valve

Fully open/closed or throttling services

Frequent operation

Minimal fluid trapping in line

The disc or wafer rotates about a vertical axis & can be turned through 90deg. .The disc seals against the opening to cut of flow & can be positioned ata point between fully closed and fully opens as required

Application: Liquids, gases, slurries, liquids with suspended solids andventilation systems

Small, light-weight, easy operation ,low cost ,minimum maintenance,drip tight shut –off , quick-acting & reliability

High capacity, Low pressure drop& self-sealing so they don’trequire an additonal flange gasket for installation

Can be used for vacuum service

Disadv:High torque required for control

Prone to cavitations at lower flows

Leaks early & only low-flow throttle

The material used for seats restrict its use for high temperatureapplication

BUTTERFLY VALVE

CHECK VALVES

Allow flow in one direction only.Allow flow in one direction only.

Flow forces a ball or disk in one direction to open the valve;Flow forces a ball or disk in one direction to open the valve;

when flow stops, the ball or disk seats to close the valve.when flow stops, the ball or disk seats to close the valve.

An important concept in check valves is the crackingAn important concept in check valves is the cracking

pressure which is the minimum upstreampressure which is the minimum upstream pressure at whichat which

the valve will operate. Typically the check valve is designedthe valve will operate. Typically the check valve is designed

for and can therefore be specified for a specific crackingfor and can therefore be specified for a specific cracking

pressure.pressure.

One common application is in the discharge line of aOne common application is in the discharge line of a

centrifugal pump to prevent reverse suctioncentrifugal pump to prevent reverse suction

AdvAdv::

Check valves are automatic in actionCheck valves are automatic in action

CHECKVALVES:CHECKVALVES: HOW THEY

WORK…

CORRECT FLOW REVERSE FLOW

CHECK VALVE CLASSIFICATION

CHECK VALVE

SWING LIFT

PISTON LIFTWAFER BALL LIFT NON-SLAM

SWING CHECK

Controls direction of flowControls direction of flow

It has a hinged disk. When the water flowreverses, water pressure pushes the disk andcloses the valve

Application: Application: Suspended Particles,high velocitySuspended Particles,high velocity Adv Adv::

Minimum Pressure Drop is RequiredMinimum Pressure Drop is RequiredBest For Liquids And For Larger Line SizesBest For Liquids And For Larger Line Sizes(Above 2”)(Above 2”)

Disadv:Not Suitable In Line Subject To Pulsating FlowNot Suitable In Line Subject To Pulsating Flow

Some Styles Operates Only In A HorizontalSome Styles Operates Only In A HorizontalPositionPosition



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SWING-CHECK VALVE

WAFER CHECK VALVE

Wafer check valves are flangeless swing check valveWafer check valves are flangeless swing check valvecovered under regulatory code API 594covered under regulatory code API 594

Adv Adv::

,,reduced water hammer and are compactreduced water hammer and are compact

Disadv:Disadv:

producing relatively high head lossesproducing relatively high head losses

excessive wear under some operating conditionsexcessive wear under some operating conditions

WAFER CHECK VALVE PISTON LIFT CHECK VALVE

In a lift check valve, upward regular flow raisesthe piston and opens the valve, and reverseflow pushes the disk down to its seat and stopsthe backflow

vv::Good For Vapours ,Steam ,And Water.Good For Vapours ,Steam ,And Water.Suitable For Pulsating FlowSuitable For Pulsating Flow

Disadv:Many Design But For Horizontal Service Only.Many Design But For Horizontal Service Only.Not Common In Sizes Over 6 Inch.Not Common In Sizes Over 6 Inch.Not Recommended For Service Which DepositNot Recommended For Service Which DepositSolidsSolids

PISTON LIFT CHECK VALVEBALL LIFT CHECK VALVE

Controls direction of flowControls direction of flow

ball is located at end of stem and lifts to allow flowball is located at end of stem and lifts to allow flow Application: Space Limitation Problems, Minimum shut Application: Space Limitation Problems, Minimum shutoff is 5 psioff is 5 psi

Adv: Adv:Stop Flow Reversal More Rapidly Than OthersStop Flow Reversal More Rapidly Than Others

Good For Viscous Fluids Which Deposit SolidGood For Viscous Fluids Which Deposit SolidResidues That Would Impair Operation Of OtherResidues That Would Impair Operation Of Othertypetype

Vertical Or Horizontal Installation Is possible Vertical Or Horizontal Installation Is possibleDisadv:Disadv:

Not Common in Sizes Over 6 Inch.Not Common in Sizes Over 6 Inch.Not Suitable For Lines Subject To Pulsating FlowNot Suitable For Lines Subject To Pulsating Flow



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BALL LIFT CHECK VALVENON-SLAM CHECK VALVE

The NonThe Non--slam Check Valve Is A Springslam Check Valve Is A Spring--loadedloaded

Lift Check Valve With A Modified Design Of Lift Check Valve With A Modified Design Of

The BodyThe Body

The Valve Is Designed In Such Way That SameThe Valve Is Designed In Such Way That Same

Can Be Sandwiched Between The Two Flanges.Can Be Sandwiched Between The Two Flanges.

Here The Disc Is Held In Position By A SpringHere The Disc Is Held In Position By A Spring

Which Is Housed In A Housing Cap Or YokeWhich Is Housed In A Housing Cap Or Yoke

INSPECTION AND TESTING

Inspection plan to be submitted to Purchaser by supplierInspection plan to be submitted to Purchaser by supplierduring orderduring order

FOR FORGED VALVES/ CAST STEEL VALVESFOR FORGED VALVES/ CAST STEEL VALVES Visual and dimensional inspection. Visual and dimensional inspection.Review of material test certificates.Review of material test certificates.

Any mandatory of supplementary test. Any mandatory of supplementary test.Hydrostatic test of all valves.Hydrostatic test of all valves.Strip check on 1% of total ordered quantity of Strip check on 1% of total ordered quantity of valves at random to verify compliance withvalves at random to verify compliance withspecification requirementsspecification requirements

Review of radiographs / radiographic reports andReview of radiographs / radiographic reports andreports of any other NDT tests, for cast steel valvereports of any other NDT tests, for cast steel valveonlyonly

IBR VALVES

Valves described as “I BR Valves” shall be inValves described as “I BR Valves” shall be inaccordance wit h the lat est I BR (I ndian Boileraccordance wit h the lat est I BR (I ndian BoilerRegulations) as well as the ot her requirementsRegulations) as well as the ot her requirementsspecified in t he specification .specified in t he specification .

For SW / BW end carbon steel valves underFor SW / BW end carbon steel valves under “ ” “ ”,,shall conform to the following :shall conform to the following :

Carbon ( Max.)Carbon (Max.) :: 0.25%0.25%Others (S, P, Mn) :Others (S, P, Mn) : As per IBRAs per I BR

For all “IBR Valves” test certificate in form IIIFor all “IBR Valves” test certificate in form III--C shallC shallbe furnished, duly signed by IBR inspection authority orbe furnished, duly signed by IBR inspection authority oran IBR approved representativean IBR approved representative

All valves shall be painted red All valves shall be painted red

TERM USED FOR VALVE SPECIFIATION

PressurePressure – –t em per at ur e r at in gs:temperature ratings:

PressurePressure – –temperature rating is the maximum allowabletemperature rating is the maximum allowablesustained non shock pressure at the corresponding tabulatedsustained non shock pressure at the corresponding tabulatedtemperature. These are listed in ASME B16.34temperature. These are listed in ASME B16.34

Class:Class:

The valve is specified by the pressure rating of the body of The valve is specified by the pressure rating of the body of the valves. American Standard specified the following classesthe valves. American Standard specified the following classes(i.e. 150# ,300# ,400# ,600#,900# ,1500# & 2500 #)(i.e. 150# ,300# ,400# ,600#,900# ,1500# & 2500 #)

Trim:Trim:

The trim is comprised of stem ,seat surfaces ,back seatThe trim is comprised of stem ,seat surfaces ,back seatbushing and other small internal parts that’s normallybushing and other small internal parts that’s normallycontact the surface fluid.contact the surface fluid.

API 600 specifies trim number in table 3 of the standard ,it API 600 specifies trim number in table 3 of the standard ,itspecifies the types of material which can be used for thespecifies the types of material which can be used for theparts with its typical specification and grade.parts with its typical specification and grade.

TRIM PARTS OF COMMON VALVES

GATE GLOBE SWING LIFTCHECK

STEM STEM SEAT RING DISC GUIDE

SEAT RING SEAT RING DISC HOLDER SEAT RING

WEDGE RING DISC NUT SIDE PLUG

BUSHING BUSHING HOLDER PIN

DISC NUT PIN



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Wetted partsWetted parts:: All parts which come in contact with the service fluid are called the All parts which come in contact with the service fluid are called thewetted parts .wetted parts .

Wire drawingWire drawing::This term is used to indicate the premature erosion of the valve seatThis term is used to indicate the premature erosion of the valve seatcaused by excessive velocity between seat and seat disccaused by excessive velocity between seat and seat disc

A WOG (water A WOG (water --oiloil--gas, relatively cool liquids) disc is best defiancegas, relatively cool liquids) disc is best defianceagainst wire drawing because its resiliency make it easier to closeagainst wire drawing because its resiliency make it easier to closetightly.tightly.Stem discs are of harder material and to be closed carefully to preventStem discs are of harder material and to be closed carefully to preventwire drawingwire drawing

i i i ii i i i--i , i i ii , i i irefrigeration. The ice formation on the wedge will obstruct movementrefrigeration. The ice formation on the wedge will obstruct movementthereby increasing the leak through seat furtherthereby increasing the leak through seat further

StraightStraight – –t hr ough fl owthrough flow ::This refer to the valve in the closing element is retracted entirely sothat there is no restriction of flow

QuarterQuarter – –t ur n v alv e:turn valve:This refers to the valve where the entire operation of valve is achievedThis refers to the valve where the entire operation of valve is achievedby 90 deg. Turn of the closing elementby 90 deg. Turn of the closing element

UPSTREAM PRESSURE:UPSTREAM PRESSURE:

Pressure of the fluid entering the valve, sometimes refers toas inlet or supply pressure.

DOWNSTREAM PRESSURE:DOWNSTREAM PRESSURE:

Pressure of the fluid discharged from the valve, sometimesrefers to as outlet or reduced pressure.

LDAR:LDAR:

Signifies “ leak detection and repair” to ensure that theSignifies “ leak detection and repair” to ensure that thefugitive emission standards of EPA are met.fugitive emission standards of EPA are met.

LAER:LAER:

Signifies “ lowest achievable emission rate ” is the minimumSignifies “ lowest achievable emission rate ” is the minimumrate of fugitive emission which is achieved by deployingrate of fugitive emission which is achieved by deployingproper sealing arrangementsproper sealing arrangements

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