inspect valves (1)

8/10/2019 Inspect Valves (1)

1/124


2/124

PEW-404.01 P ARTICIPANT REVISIONS

DATE REVISION DESCRIPTION P AGE (S ) AFFECTED

&' ' * C O+",#T# -# /S/O0S.%. 1AS2A S. CA # +. A33A$

i


3/124


4/124

PEW-404.01 P ARTICIPANT TABLE OF CONTENTS

#-/67 A, # /$#0T/6/CAT/O0 6-O+ +A-3/09S

alve /dentification

Symbols for +etallic and 0on:+etallic materials

/0S"#CT A, #S

0ew alves ( endor /nspection)

6ield /nstallation inspection

-eceiving /nspection

6ield Tests

6ield /nstallation ,imitations

#xisting alve /nspection

Safety during inspection

-ebuilt or repaired valve

6re;uently Occurring "roblems

Operating $ifficulties

Other "roblems

Assurance Tests

-ecords

alve


5/124

PEW-404.01 P ARTICIPANT TABLE OF CONTENTS

#=#-C/S# >&. /$#0T/67 A, #S

#=#-C/S# >'. /$#0T/67 "?/$ A, # S7+1O,S

#=#-C/S# >@. /$#0T/67 T2# +A/0 "A-TS O6 A 9AT# A, #

#=#-C/S# >*. /$#0T/67 T2# +A/0 "A-TS O6 A 9,O1# A, #

#=#-C/S# > . +#AS%-# A,# 1O-# S/B# A0$ 6,A09# S/B#

#=#-C/S# > . ,OCAT# S"#C/6/C A, #S O0 A "/"/09 A0$/0ST-%+#0TAT/O0 $-AD. /0S"#CT A $#6#CT/ # A, #

#=#-C/S# >E. $#T#-+/0# A,# F. /$#0T/67 +A-3/09S O0 A A, #

#=#-C/S# >& . O1TA/0 A $-A


6/124

PEW-404.01 P ARTICIPANT OBJECTIVES

OBJECTIVES

Terminal Obje !i"e

%pon completion of this module the "articipant will be able to inspect valves inaccordance with applicable standards.

Enablin# Obje !i"e$

/n order to accomplish the Terminal Ob5ective the participant will be able to do thefollowing

/dentify valves and valve parts.

erify valve identification from mar8ings

/nspect valves

Note: This training material has been developed using the latest available versions of applicableaudi !ramco and industr" standards. #o$ever% these documents are regularl" updated.Therefore% it is the responsibilit" of the &nspector to ensure that he is conducting hisinspections according to the latest% updated version of these documents .

&


7/124

PEW-404.01 P ARTICIPANT INFORMATION

INTRODUCTION

/n the petroleum industry the primary responsibility of the inspector is to ensure plantsafety ensure ;uality of materials and achieve maximum plant reliability and efficiency.

The piping system ma8es up a ma5or part of any petroleum processing operation. "roper inspection and maintenance of the piping system is vital to Saudi Aramco interests.

There are many parts to a piping system. The valve is a very important part of the pipingsystem. The valve is a mechanical device that is used to control the flow of li;uids andgases through the piping system.

alves are manufactured in a wide range of siIes types styles and materials. This isdue to the wide range of system products and operating temperatures that may bepresent in piping systems.

This module shows you how to identify different valves and their component parts. Thismodule also shows you how to inspect these valves.

'


8/124


IDENTIF% VALVES AND VALVE PARTS

6or an inspector to do a better 5ob he must have a good basic understanding of thee;uipment that he will be inspecting. /n the case of valves the inspector must be able toidentify the type of valve and its function within the piping system. 2e should be able toidentify the parts of the valve and their function. The inspector should also be able toidentify the type of material used in the valve and the valve parts.

The most common mechanical device used in Saudi Aramco plants is the valve. alvesin any piping system serve four basic functionsJ

&. Shut off or open a system to fluid flow

'. -egulate or throttle any fluid flow

@. "revent bac8flow

*. -elieve pressure

alve installation may be in the normally:open position or the normally:closed positiondepending on the particular re;uirements. 6or example an unloading valve at a storagetan8 is normally closed. The valve would only be opened when the tan8Gs contents arere;uired to be discharged. An example of a normally:open valve would be a pumpdischarge valve.

6or functions that re;uire only a fully:open or fully:closed position during operation thegate valve is the valve of choice.


9/124


Chec8 valves

"ressure relief valves

alves come in a wide range of siIes from & * inch to *' inches and sometimes larger.alves are classified according to the pressure they can withstand. alves come inpressure class ratings of & @ * E F & ' and * poundsper s;uare inch ("S/).

Note: 'lass (00 is not normall" tabulated ! )E *1+.,4 designation% but it is anintermediate class that is $idel" used for soc et $elding and threaded end valves.

alves are designed to meet specific operating needs. The type of process and the

characteristics of the process material will determine the type class siIe and functionof the valve. 0ot only is there an assortment of various valve types but there is also achoice of materials various pressure ratings and finally the type of connection in a givenpiping system. There is also a choice of the various types of manual mechanical andautomatic controlled operators. Some things that determine the type of valve used areJ

Speed of operation re;uired

Amount of positive shut:off re;uired

2ighly erosive or corrosive service

Temperature of the process material

"ressure in the piping system

Amount of vibration present

Available space

#xpense

A&&li able S!an'ar'$

The inspector needs to be familiar with the following standardsJ

*:SA+SS: @ 9eneral -e;uirements for alves

*:SA+SS: *E alve /nspection and Testing -e;uirements

*


10/124


11/124


* HSA+SS: & 1all alves A"/ $

*: SA+SS : ' 1all alve A"/ A

6orm &D : *@ alve +aterial Certification re;uirements 6orms *@*@ & *

Bl * Val"e$

1loc8 valves either allow flow or bloc8 the flow of fluid through a piping system. They arenormally operated either in the full open or full closed position.

Some of the most common bloc8 valves used at Saudi Aramco areJ

9ate valve

"lug valve

1all valve

2igh:performance butterfly valve

Ga!e Val"e$

About D percent of all valves in process plants are gate valves. +ost valves in processplants function as bloc8 valves. 1loc8 valves are re;uired only to fully shut off or fullyturn on flow (See 6igure &). The gate valve is an optimum engineering and economicchoice for this on or off service.

9ate valves are available in the full range of pipe siIes AS+# A0S/ 1& .@*pressure temperature ratings and materials that are encountered in process plantapplications. A gate valve is not suitable to throttle flow because it will pass themaximum possible flow while it is only partially open. /n addition the valve seatingsurfaces can erode rapidly from fluid flow when the valve is not in the fully open or fullyclosed position.

6igure &A shows a flanged gate valve in the fully:open position with the drawing symbolbelow. 6igure &1 shows a flanged gate valve in the fully:closed position with the drawingsymbol below.


12/124


Fi#+re ,- Flan#e' #a!e "al"e

F+n !i n

The off on flow control of a gate valve is achieved by moving a gate into or out of thefluid:flow stream.


13/124


Fi#+re .- Main &ar!$ / a #a!e "al"e

B '0 Pa!!ern

+ost standard gate valves are available in either cast or forged steel body constructionup to about & mm (* in.) 0"S. 1ody castings are usually supplied for larger gatevalves because of the cost and difficulty associated with forging the relatively complexshapes of gate valves in the larger siIes. There are three types of body patternsJ full:portand venturi:port or reduced ports.

ull Port

The line siIe flow area and resulting minimum pressure drop of the full:port valvema8e it suitable for all process plant applications where a gate valve is re;uired./ts use is mandatory for systems where pipe scrapers must be employed.2owever a full:port valve is usually not the most economical selection sincereduced:port: and venturi:type valves are less expensive. "er A"/ teel

/ate alves - langed and *utt-Welding Ends full:port is specified for all flangedvalves.

enturi or educed-Port

/n the venturi: or reduced:port valve the seat opening is one or more pipe siIesless than the valve siIe. This reduces the valve cost due to the overall smaller valve casting siIe. 2owever the reduced seat siIe increases valve pressuredrop reduces its strength to absorb loads from the piping system and does not

E


14/124


permit use of pipe scrapers. -educed:port valves are available only up to &mm (* in.) in siIe and are the normal choice in small diameters. A reduced:port isspecified for valves that are specified to meet A"/ ' 'ompact teel /ate

alves .

Ga!e$

There are several different gate designs. The solid: and flexible:wedge gates are themost common. *:SA+SS: & defines gate:type re;uirements for different valve siIesand ratings. 6or example a flexible wedge is re;uired for valves & mm (* in.) 0"Sand larger in AS+# A0S/ classes & through .

olid-Wedge /ate

The solid:wedge gate is the lowest cost and most widely used gate:type in

process plants. Solid:wedges are of one:piece construction and the seatingsurfaces are precision machined with a wedge taper. A precision:dimensionalmatch between the gate and the body seating surfaces is re;uired to obtain atighter seal. The solid wedge gate is favored for its strong and simple design butit is prone to stic8ing when used in services where extreme temperature changesor gradients KLTM &F*NC (@ N6) cause the valve body to contract more than thegate.

le2ible-Wedge /ate

The flexible:wedge gate is the second most widely used type. Although similar tothe solid wedge the flexible wedge contains a deep annular groove in the gatemidway between the two seating surfaces. This groove reduces the rigidity of thegate and allows slight relative flexing between the seating surfaces. This flexingallows the disc seating surfaces to accommodate some thermal movement or dimensional misalignment between the gate seats and the body seats. 6or thisreason the flexible:wedge gate is more suitable than the solid:wedge gate for high:temperature applications and is less prone to gate stic8ing.

B nne!$

The valve bonnet is a pressure:retaining component that supports the valve stem andoperating mechanism and contains the stem:to:bonnet pac8ing gland seal system. Thebonnet 5oint provides a pressure:tight closure between the process fluid and atmosphereat the 5unction between the bonnet and the valve body. The primary bonnet types includebolted welded pressure:seal seal:welded threaded union and screwed. 1olted andscrewed are the most common bonnet types.

*olted *onnet

A typical bolted bonnet is shown in 6igure @. The bolted bonnet uses flangedconstruction to permit its removal from the valve body thus giving completeaccess to the valve stem gate and body seat for maintenance. 1ecause of the

F


15/124


bolted:flange gas8et detail this design is sub5ect to the same potential lea8ageproblems as a normal pipe flange. Therefore the bonnet should be treated in thesame manner as a pipe flange with regard to bolting and gas8et selection. The

bolted bonnet is the most practical and commonly used design for process plantgate valves and is available in all siIes and AS+# A0S/ pressure temperatureratings.

Fi#+re 1- B l!e' b nne!

cre$ed *onnet

The screwed:in bonnet as shown in 6igure * is threaded externally and screwedinto an internally threaded valve body. An alternative design is the screwed:onbonnet where the bonnet is internally threaded and screwed onto an externallythreaded body.

Although of low cost and simple design the screwed bonnet has severaldisadvantages. 6irst the threaded 5oint is susceptible to loosening whensub5ected to vibration or through the application of stem tor;ue on the gland.Second screwing the bonnet firmly to the body nec8 tends to distort the bodynec8 or bonnet. /t is therefore more difficult to achieve and maintain a tight sealwith a screwed bonnet valve than with the other types. Therefore this type of bonnet should be considered for use only in small K mm (' in.) or less lowrating (Class & or less) bronIe and steel valves in clean non:corrosive utilitytype services.

&


16/124


Fi#+re 2- S re3e' b nne!

Trim

A"/ P teel /ate alves% langed and *utt-$elding Ends3 defines gate valve trim asfollowsJ

the stem

the body seat surface

the gate seat surface

the bushing or weld:deposit used for the bac8seat and stem hole guide and

small internal parts that normally contact the service fluid excluding the pin used inma8ing a stem:to:gate connection (the pin is specified to be an austenitic stainless steel).

Trim material is selected to prevent galling or metal wear of surfaces in sliding contactwith each other and to minimiIe corrosion and erosion effects. A"/ lists & differentnominal trims by composition of seating materials and their associated hardness.

S!em$

The stem raises and lowers the gate. /t is designed to withstand the forces that aregenerated during movement of the gate which creates compression and tension in thestem. 2owever the stem is not designed to resist the fluid forces that act on the disc.

A loose stem:to:gate connection is provided to permit the fluid forces that act on the gateto be transmitted to body gate guides which are provided for that purpose. The stem isprovided with some form of threading which upon turning causes it to drive the gate upor down. 9ate valves can have either a non:rising stem or a rising stem. 6igure showsa non:rising:stem gate valve.

&&


17/124


Fi#+re 4- N n5ri$in# $!em Ga!e "al"e

The rising:stem gate valve is preferred at Saudi Aramco because the operator can easilytell if the valve is open or closed by the position of the stem. 6or example the stem in6igure is up. This indicates that the valve is open. /f the stem were all the way down itwould indicate that the valve was closed.

A rising:stem gate valve ta8es up more space than a non:rising:stem gate valve. /f space is limited the non:rising:stem gate valve can be used.

&'


18/124


19/124


Fi#+re 7- S!em &a *in# $0$!em 3i!8 lan!ern rin#

Sea!$

The extent to which tight shutoff is accomplished depends directly on the sealing abilityof the seating surfaces consisting of body seats and gate seats. The ability of twocontacting surfaces to form a seal is a function of the degree of surface conformabilitybetween them. "erfect contact (i.e. no voids) gives Iero lea8age but this cannot beachieved in practice since an absolutely smooth surface with & Q conformabilitycannot be attained. The problem therefore is to achieve sufficient conformability to 8eepthe lea8age rate within acceptable limits. There are two general categories of valveseatsJ the hard seat with metal:to:metal contact and the soft seat with a metal:to nonmetal primary contact.

#ard eats

2ard seats are more economical can be used at higher pressures andtemperatures and are the most common seat design used in gate valves. Thebody:seating surface may be designed as a separate seat ring which is threadedor welded into the valve body or be integral with the valve body. 6igure Eillustrates the integral seat design. /ntegral seats will typically be used only for small siIe valves. *:SA+SS: & /ate alves specifies seat ring designre;uirements.

oft eats

Soft seats provide better shutoff approaching ero lea age. 2owever the softseat materials that are used (such as Teflon or iton) limit the maximum:usetemperature of the valve to a level that is much lower than the valve AS+# A0S/pressure class.


20/124


Fi#+re 9- In!e#ral $ea!

A'"an!a#e$ / Ga!e Val"e$

They have good shut:off characteristics.

They are bidirectional.

The pressure loss through the valve is minimal.

Di$a'"an!a#e$ / Ga!e Val"e$

9ate valves are not ;uic8 opening or closing valves. 6ull:stem travel to open or close a gate valve re;uires many turns of its hand wheel or an actuator.

9ate valves re;uire large space envelope for installation operation andmaintenance.

The slow movement of the disc near the full:closed position results in high:fluidvelocities causing scoring of seating surfaces referred to as wire drawing. /t also causesgalling of sliding parts.

Some designs of gate valves are susceptible to thermal or pressure bindingdepending upon the application.

/n systems experiencing high:temperature fluctuations wedge:gate valves mayhave excessive lea8age past the seats due to changes in the angular relationship betweenthe wedge and the valve seats caused by piping loads on the valve ends.

-epair or machining of valve seats in place is difficult.

&


21/124


Pl+# Val"e

"lug valves usually function as bloc8 valves to fully shut off or fully open flow. They are

well suited for conditions where ;uic8 on off and or bubble:tight shut:off are re;uired.

6igure FA shows a plug valve. 6igure F1 shows the "?/$ symbols for a threaded plugvalve. 0otice that the plug valve is operated by a handle instead of a wheel. The plugvalve operates much faster than a gate valve. Only & * turn of the handle will change theplug valve from fully closed to fully open.

+ost plug valve styles are available in the full range of pipe siIes and materials that areneeded in process plant applications. Soft:sealed styles with full cylindrical plugs aresuitable for double:bloc8 and bleed applications.

The soft:seal types however may have lower temperature pressure ratings than those

given in AS+# A0S/ 1& .@* for steel valves because of the lesser physical propertiesof the soft:seat materials. Soft:seal plug valves are not normally used for throttlingservice since the soft seals are sub5ect to erosion or distortion displacement caused byfluid flow when the valve is not in the fully open or closed position. A plug valve is a goodchoice as a bloc8 valve when used within the limitations noted above and when bubble:tight shutoff or ;uic8 on off operation is re;uired.

Fi#+re :- Pl+# Val"e

&


22/124


F+n !i n

The plug valve utiliIes a cylindrical and usually tapered plug to provide ;uarter:turn

operation from fully open to fully closed. A hole is provided through one axis of the plugconnecting the inlet and outlet ports of the valve body for straight:through flow when inthe open position and completely bloc8ing flow when rotated F N to the closed position./n the closed position tight shutoff is obtained either by sealant in5ected into theplug body cavity interface or by resilient seat:to:metal seat:sealing contact (as in a soft:seated ball valve).

A plug valve has seven main parts that are listed belowJ (See 6igure & )

2and lever

"ort

1ody

Stem

1onnet

"ac8ing

"lug

Fi#+re ,;- Main &ar!$ / a &l+# "al"e-

&D


23/124


T0&e$

There are three basic plug valve:typesJ the lubricated non:lubricated and soft:sealed

fire safe. 0on:lubricated non:fire safe plug valves have few applications in processplants and will not be discussed.

5ubricated Plug alve

A lubricated plug valve depends on in5ection of a sealant to prevent lea8agearound the plug through the interface between the plug and the body cavity. Thesealant is in5ected through a pressure fitting into the body cavity and distributedacross all seating surfaces via grooves in the plug. The sealant material must becompatible with the process fluid resist brea8down at maximum designtemperature and retain its fluidity and lubricating properties at minimum designtemperature.

,ubricated plug valves can provide good long:term performance if ade;uatemaintenance attention can be ensured.


24/124


the smallest port area for a given nominal valve siIe. Their use restrictions are the sameas for regular pattern valves. The round:port full:bore pattern is the most expensive for agiven nominal siIe but is re;uired where pressure drop is critical or where scraping will

be re;uired.

Pl+# S!0le$ an' Sea!in# Me 8ani$m$

The plug opens or closes the flow path through the valve. A full or reduced:bore holethrough one axis of the plug permits straight:through flow when aligned with thelongitudinal valve axis and flow is bloc8ed when the plug is rotated F N to the closedposition.

Common plug configurations are the full cylindrical (usually tapered) and eccentric:cylindrical segment styles. The most common style is the full:cylindrical tapered plugwith sealant grooves for the lubricated:type valve or resilient:seat inserts for the soft:

seal:type valve. This configuration is best suited to the constant wedge: seatingmechanism used with lubricated plugs and to the lift:off turn and reseat design used for some non:lubricated types.

Sea!$

The degree of closure afforded by a plug valve depends on the sealing capability of theplug and body seats.


25/124


by replacement of sleeve in addition to utiliIing the wedging action of a tapered plug.

+ultiple port design helps reduce number of valves needed and permits change in

flow direction

Di$a'"an!a#e$ / Pl+# Val"e$

-e;uires greater force to actuate due to high friction.

0"S * ($0 & ) and larger valves re;uire use of actuators.

-educed port due to tapered plug.

Typically plug valves may cost more than ball valves.

Ball Val"e

1all valves usually function as bloc8 valves to fully shut off or fully open flow. 1all valvesare well suited for conditions where ;uic8 on off and or bubble:tight services arere;uired. The ball valve is available in the full range of pipe siIes and materials that areneeded in process plant applications.

6igure &&A shows a ball valve. 6igure && 1 shows the drawing symbol for a ball valve.0otice that the ball valve is operated by a handle instead of a wheel. The ball valve li8ethe plug valve re;uires only & * turn of the handle to change the valve from fully closed

to fully open.

Fi#+re ,,- Ball "al"e

'


26/124


Soft:sealed ball valves are usually suitable for double:bloc8 and bleed applications.2owever it is important to note that pressure temperature ratings for ball valve softseats above ambient temperatures are usually lower than the AS+# A0S/ ratings for

steel valves. This is because of the lower physical properties of the soft:seat materials.Soft:sealed ball valves are not normally used for throttling service because the valve softseats are sub5ect to erosion or distortion displacement caused by fluid flow when thevalve is not in the fully open or fully closed position.

The soft:sealed ball valve is a good choice as a bloc8 valve when used within thelimitations previously mentioned and when bubble:tight shutoff double:bloc8 and bleedcapability or the ;uic8 on off feature is re;uired.


27/124


28/124


Fi#+re ,1- Sea! rin#$

B '0

The body of a ball valve supports the ball stem and operating mechanism. There areseveral body designs available but all fall into the two basic categories of one:piece or multi:piece designs.

)ulti-piece *od"

/n the multi:piece body design the valve body is circumferentially divided intopieces thereby permitting the ball and seats to be installed or removed bydisassembling the body.

The body segments are fastened together by flanging screwing or with longthrough:bolts. 2owever the exposed through:bolt arrangement is notrecommended for fire safe valve applications as direct flame impingement cancause bolt relaxation and substantial external 5oint lea8age. The multi:piece bodyis acceptable for use in all utility services but must be certified fire safe for use inhydrocarbon services. The vendor should certify that the body 5oint(s) arecapable of withstanding full:pipe stresses with no resultant 5oint lea8age.

8ne-piece *od"

There are three basic one:piece body designsJ the end:entry top:entry andsealed (welded) designs.

/n the end:entry:type the ball and seats are installed axially and retained by anaxial retaining ring. One desirable feature of this design is the ability to eliminateone external lea8age path by eliminating one body 5oint usually re;uired on other types for ball and seat installation. 2owever this configuration has a safetyhaIard in that faulty retention of the ball could result in blowout when thedownstream flange of the valve is disconnected under pressure unless theretaining ring design can be loc8ed in.

/n the top:entry body:type the ball and seats are fit into the top of the valve andretained by a cover or bonnet. This body construction permits inline maintenanceof the valve to the extent of replacing the ball or seats. This is a particular advantage for valves that are butt:welded seal:welded or soc8et:welded into theline.

The sealed:body design uses welded construction. The ball and seats arepositioned in the body before welding the body seams.


29/124


30/124


31/124


32/124


body and disc. The soft seats permit bubble:tight shut:off and the full lining enhanceserosion and corrosion resistance.

1utterfly valves are suitable for low:pressure and low:temperature applications as wellas high:pressure and high:temperature applications. The term high-performancebutterfl" valve is intended to signify their suitability for moderate to high pressure andtemperature services. The butterfly valves have a low:pressure drop and high:pressurerecovery factor. They are suitable for low:pressure drop applications. These valves areextensively used in large water transmission distribution and cooling water lines.

C n$!r+ !i n / a B+!!er/l0 Val"e

A butterfly valve has a short circular body a round disc shaft metal:to:metal or softseats top and bottom shaft bearings and the stuffing box. The valve body may haveflanged ends lugs or wafer style. Configurations to be installed between pipe flanges.

The welding:end butterfly valves are usually large and have butt:welding ends.

Sometimes butterfly valves are manufactured in rectangular or s;uare configurations.The wafer:style butterfly valves are usually available in siIes 0"S &' ($0 @ ) or smaller. The limitation on siIe is essentially imposed by the difficulty of holding the larger weight valve in place between the flanges. The lug and flanged:end butterfly valves areavailable in all siIes and pose no problem in installation between flanges except for thenormal problems associated with warped:flanged surfaces and uneven tor;uing of bolts.

A butterfly valve has seven main parts which are listed below (See 6igure & )J

2and lever

Seat

Stem

1ody

0ec8 bushing

Stem seal

$isc

'D


33/124


Fi#+re ,6- Main &ar!$ / a B+!!er/l0 "al"e

T0&e$ / B+!!er/l0 Val"e$

5o$ Pressure or 'oncentric *utterfl" alves

/n low pressure and low temperature designs of butterfly valves the disc andshaft axes are concentric . /n open position the disc divides the flow in two e;ualhalves with the disc in the middle and parallel to the flow. These valves areprovided with resilient seats. These valves are available as lined or unlined. +ostcommonly used lining and seating materials includeJ 1una 0 0eoprene6luorcel 2ypalon #"$+ T6# iton among others. The applicationtemperature is limited by the temperature capability of the resilient material.These valves are generally produced in Classes & and @ .

#igh-Performance or Eccentric *utterfl" alves:

The disc in high performance butterfly valves is offset from the center of thevalve and the shaft is also offset from the center of the disc. The offsets provided

'E


34/124


allow the disc to move eccentrically uninterrupted away from or toward the valveseat. Thus the uninterrupted motion of the disc until it seats against the valveseat prevents unwanted wear and tear of the valve seat and disc due to friction

and rubbing of the seating surfaces. Some butterfly valve manufacturersproduce high performance butterfly valves with triple offset which enhances their actuation and lea8 tightness.

A'"an!a#e$ / B+!!er/l0 Val"e$

The following summariIes the advantages of butterfly valvesJ

The compact design re;uires considerably less space compared to gateglobe or other valves.

,ight in weight.

Ruic8 acting as a ;uarter:turn valve it re;uires less time to open or close.

/t is available in large siIes ranging from 0"S& to over 0"S ' ($0 ).

They have low:pressure drop and high:pressure recovery.

"rovide bubble:tight service.

Di$a'"an!a#e$ / a B+!!er/l0 Val"e

Throttling service is limited to low differential pressure.

Throttling is restricted to a @ : to E :degree disc opening. ,ocation of valvepipe routing free and closed discharge are to be considered while using abutterfly valve in a throttling application.

Cavitation and cho8ed flow are two potential concerns.

The disc movement is unguided and affected by flow turbulence.

T0&i al A&&li a!i n$ / B+!!er/l0 Val"e$

Concentric or low:pressure and low:temperature butterfly valves the high:performancebutterfly valves cover a wide range of applications. These applications includeJ

Cooling water air gases and other similar applications such as fire protectioncirculating water

Corrosive services re;uiring lined valves

'F


35/124


6ood processing chemical and pharmaceutical services

Slurry and similar services

2igh:pressure and high:temperature water and steam services

Throttling service involving low differential pressures as in cooling water or air supply systems

acuum service

Gl be Val"e

Conventional globe valves may be used for isolation and throttling services. Althoughthese valves exhibit slightly higher pressure drops than straight through valves (e.g.gate plug ball etc.) they may be used where the pressure drop through the valve is nota controlling factor.

6igure &DA shows a flanged globe valve fully open with the drawing symbol below.6igure &D1 shows a globe valve in the throttled position. 6igure &DC shows the drawingsymbol for a globe valve

Fi#+re ,7- Gl be "al"e

9lobe valves are extensively employed to control flow. The range of flow controlpressure drop and duty must be considered in the design of the valve to avertpremature failure and to assure satisfactory service. alves sub5ected to high:differential

@


36/124


pressure:throttling service re;uire specially designed valve trim. 9enerally the maximumdifferential pressure across the valve disc should not exceed ' percent of the maximumupstream pressure or ' psi (&@E 8"a) whichever is less. alves with special trim

may be designed for applications exceeding these differential pressure limits.

T0&e$ / Gl be Val"e$

Tee Pattern

9lobe valves have the lowest coefficient of flow and higher pressure drop. Theyare used in severe throttling services such as in bypass lines around a controlvalve. Tee:pattern globe valves may also be used in applications where pressuredrop is not a concern and throttling is re;uired.

W"e Pattern

9lobe valves among globe valves offer the least resistance to flow. They can becrac8ed open for long periods without severe erosion. They are extensively usedfor throttling during seasonal or startup operations. They can be strong through toremove debris when used in drain lines that are normally closed.

!ngle Pattern

9lobe valves turns the flow direction by F degrees without the use of an elbowand one extra weld. They have a slightly lower coefficient of flow than wye:pattern globe valves. They are used in applications that have periods of pulsatingflow because of their capability to handle the slugging effect of this type of flow.

C n$!r+ !i n / a Gl be Val"e

9lobe valves usually have rising stems and the larger siIes are of the outside screw:and:yo8e construction. Components of the globe valve are similar to those of the gatevalve. This type of valve has seats in a plane parallel or inclined to the line of flow.+aintenance of globe valves is relatively easy as the discs and seats are readilyrefurbished or replaced. This ma8es globe valves particularly suitable for services whichre;uire fre;uent valve maintenance.


37/124


$isc

"ac8ing

Seat

9land follower

1ody

"ac8ing gland

Fi#+re ,9- Main &ar!$ / a #l be "al"e

The principal variation in globe:valve design is in the types of discs employed. "lug:typediscs have a long tapered configuration with a wide bearing surface. This type of seatprovides maximum resistance to the erosive action of the fluid stream.

/n the composition disc the disc has a flat face that is pressed against the seat openingli8e a cap. This type of seat arrangement is not as suitable for high differential pressurethrottling.

The conventional disc in contrast to the plug type provides a thin contact between thetaper of the conventional seat and the face of the disc. This narrow contact area tends tobrea8 down hard deposits that may form on the seats and facilitates pressure:tightclosure. This arrangement allows for good seating and moderate throttling.

/n cast:iron globe valves disc and seat rings are usually made of bronIe. /n steel:globevalves for temperature up to D N6 (@FFNC) the trim is generally made of stainless steeland so provides resistance to seiIing and galling. The mating faces are normally heat:treated to obtain differential hardness values.

@'


38/124


Other trim materials including cobalt:based alloys are also used. The seating surface isground to ensure full:bearing surface contact when the valve is closed. 6or lower pressure classes alignment is maintained by a long disc loc8nut. 6or higher pressures

disc guides are cast into the valve body. The disc turns freely on the stem to preventgalling of the disc face and seat ring. The stem bears against a hardened thrust plateeliminating galling of the stem and disc at the point of contact.

A'"an!a#e$ / a Gl be Val"e

9ood shutoff capability

+oderate to good throttling capability

Shorter stro8e (compared to a gate valve)

Available in tee wye and angle patterns each offering uni;ue capabilities

#asy to machine or resurface the seats


39/124


Nee'le Val"e

0eedle valves generally are used for instrument gauge and meter line service. ery

accurate throttling is possible with needle valves and therefore they are extensivelyused in applications that involve high pressures and or high temperatures. /n needlevalves the end of the stem is needle point.

6igure &FA shows a needle valve. 6igure &F1 shows the drawing symbol for a needlevalve.

Fi#+re ,:- Nee'le "al"e

A needle valve has six main parts which are listed belowJ

0eedle

1onnet

Seat

1ody

Stem

2and wheel

Dia&8ra#m Val"e

$iaphragm valves are multi:turn corrosion:proof valves used to control the flow of

@*


40/124


corrosive and dangerous system products. This is accomplished by changing theposition of a flexible diaphragm between the fully:closed and fully:open positions. Assuch they may be operated open throttled or closed. 6igure ' A shows a diaphragm

valve in the fully:open position. 6igure ' 1 shows a diaphragm valve throttling the flow.

A diaphragm valve is a pac8 less valve that uses a flexible diaphragm which functionsas both a closure and a seal.


41/124


C n$!r+ !i n / a Dia&8ra#m Val"e

$iaphragm valves consist mainly of the following (See also 6igure '&)J

A rigid body formed with a weir placed in the flow path

A flexible diaphragm which forms the upper pressure boundary of the valve

A compressor which is used to force the diaphragm against the weir

The bonnet and hand wheel which secure the diaphragm to the body andactuate the compressor

Stem

Seat

$iaphragm valves are manufactured in a variety of end connectionsJ welding end soc8etor butt welding flanged screwed or threaded clamp ends or grooved ends solventcement 5oint ends for themoplastic valves and male sanitary threaded ends.

Fi#+re .,- Main &ar!$ / a 'ia&8ra#m "al"e

The valve body is available in two patternsJ tee:pattern and angle pattern. $iaphragmvalves are available in a wide choice of body diaphragm and lining materials that aresuitable for service with a wide variety of chemicals.

6or severe corrosive applications diaphragm valves are made of stainless steel or " Cplastics or they are lined with glass rubber lead plastics titanium or still other materials.

@


42/124


43/124


Fi#+re ..- S!rai#8!3a0 !0&e Dia&8ra#m Val"e

A'"an!a#e$ / Dia&8ra#m Val"e$

Can be used as on:off and throttling service valves.

Offer good chemical resistance due to variety of linings available.

Stem lea8age is eliminated.

$oes not have poc8ets to trap solids slurries and other impurities. /t is suitablefor slurries and viscous fluids.

These valves are particularly suitable for haIardous chemicals and radioactivefluids.

These valves do not permit contamination of flow medium thus they areused extensively in food processing pharmaceutical brewing and other

Di$a'"an!a#e$ / Dia&8ra#m Val"e$

The weir may prevent full drainage of piping.


44/124


The diaphragm may experience erosion when used extensively in severethrottling service containing impurities.

$iaphragm valves are available in limited siIes usually 0"S& : &' ($0 & to@ )

An#le Val"e

An angle valve is a globe valve which is combined with the function of a F :degreeelbow. Angle valves are used when a throttling valve is needed where the piping ma8esa F :degree turn.

Standard globe valves and angle valves come in class ratings from & to and in

siIes from & ' inch to &' inches.

6igure '@A shows an angle valve. 6igure '@1 shows the drawing symbol for an anglevalve.

Fi#+re .1- An#le "al"e

@F


45/124


A+! ma!i C n!r l Val"e$

The automatic control valve is similar to a globe valve because it also is used to controlthe rate of flow. 2owever unli8e valves in a piping system that primarily serve to shutoff drain fill or divert control valves are a part of an automated control system. 6igure'*A shows an automatic control valve. 6igure '*1 shows the "?/$ symbols for anautomatic control valve.

Automatic control valves are considered the UUfinal control element!! in an automated andusually very sophisticated UUcontrol loop.!! Aside from the control valve the UUloop!!consists of a transmitter that measures the variable to be controlled (usually pressureflow level or temperature) and a controller.

6ollowing an error in the variable to be controlled (such an error being sensed by the

transmitter) the controller sends a signal change to the control valve which in turnresponds by altering the flow rate through the valve sufficiently to restore the desiredvariable (such as pressure for example).

As such automatic control valve has no wheels handles or levers to operate. The topof an automatic control valve has a diaphragm that moves the valve stem. An instrumentcontrol system changes the pressure on the diaphragm to open close or ad5ust thevalve. Automatic control valves are found throughout any large plant and are used tocontrol such things as temperature flow li;uid level and pressure.

Fi#+re .2- A+! ma!i n!r l "al"e

*


46/124


C8e * Val"e$

A chec8 valve is used to prevent bac8flow. The system product is often re;uired to flowin one direction only. The chec8 valve prevents the product from ever flowing in thewrong direction

S3in#5T0&e C8e * Val"e


47/124


"ivot pin

$isc seat

1ody

"ivot arm

6lange

Fi#+re .6- Main &ar!$ / a $3in#5!0&e 8e * "al"e

Li/! C8e * an' Ball C8e * Val"e

The lift chec8 valve and the ball chec8 valve depend upon the force of gravity for closure. /f product flow in the proper direction should stop gravity will force the ball typeand lift:type of chec8 valves to close.

A lift:type or ball:type of chec8 valve designed for horiIontal operation will not functionproperly in the vertical position. 6igure 'DA shows a lift:type of chec8 valve for horiIontalinstallation and 6igure 'D1 shows a lift:type of chec8 valve for vertical installation.6igure 'DC shows a ball:type of chec8 valve for horiIontal installation and 6igure 'D$

*'


48/124


shows a ball:type of chec8 valve for vertical installation.

Fi#+re .7- Li/!5!0&e 8e * "al"e

Another type of chec8 valve is the piston type shown in 6igure 'EA. 6igure 'E1 shows alift:type of chec8 valve while 6igure 'EC shows a ball:type of chec8 valve. The functionof all chec8 valves regardless of the type is to prevent bac8flow.

*@


49/124


Fi#+re .9- Cr $$5$e !i n$ / a 8e * "al"e

A'"an!a#e$ / C8e * Val"e$

They are self:actuated and re;uire no external means to actuate the valveeither to open or close. They are fast acting.

Di$a'"an!a#e$ / C8e * Val"e$

Since all moving parts are enclosed it is difficult to determine whether the valveis open or closed. 6urthermore the condition of internal parts cannot beassessed.

#ach type of chec8 valve has limitations on its installation configurations.

alve disc can stic8 in open position.

Pre$$+re Relie/ Val"e$

A pressure:relief valve is a self:operating valve that is installed in a process system toprotect against over:pressuriIation of the system.


50/124


A pressure:relief valve is installed in a process system where excess pressureconstitutes a safety concern of the piping or e;uipment bursting or where an abnormaloperating condition could damage the process product. 6ollowing the de:pressuriIation

of the process line to safe or normal limits the pressure:relief valve automatically closesagain to allow for normal system operation. "ressure:relief valves can be used for bothgas and li;uid services although design varies with each.

"ressure:relief valves are divided into two families according to application. One is relief valves and the other is safety valve

Note: or more information on pressure-relief valves% refer to ne2t )odule 404.0 ; erif" in-place testing of safet" valves3

*


51/124


VERIF% VALVE IDENTIFICATION FROM MAR


52/124


Fi#+re .:- P=ID

*D


53/124


6igure @ shows some of the "?/$ valve symbols on a larger scale. #ach type of valvehas a specific symbol. 0ormally:closed valves are shown as a solid blac8 shape on thedrawing.

Fi#+re 1;- P=ID "al"e $0mb l$

Val"e I'en!i/i a!i n

alves are fully described in manufacturersG catalogs and are identified through anumbering system that contains a full description of the valve in terms of type pressurerating connecting end preparation and the details of the various trim materials.

Sometimes a valve fails because it has the wrong pressure rating or the valve may notbe constructed of the proper materials for the service in which it is operating. /n the caseof new wor8 the valve material should be verified to prevent a possible future failure. /neither case the inspector must be able to determine the pressure rating of the valve andidentify the valve body and trim materials.

On many valves and particularly those for high:pressure applications the valve classrating body and trim materials and other information are mar8ed on a valve/dentification "late. 6igure @& shows a typical valve /dentification "late.

*E


54/124


Fi#+re 1,- I'en!i/i a!i n n !8e "al"e

alves are generally identified by manufacturer class and siIe. This information and thetype of metal used in the valve body is either cast or stamped into the valve body (See6igure @'). /n the case of chec8 valves and globe valves an arrow ( >>? ) is cast into thebody of the valve to indicate re;uired direction of product flow through the valve.

9eneral mar8ing re;uirements for valves are specified by AS+# & .@* and +SS S": ' . Additional body and trim material identification is located in SA#S:,: E.

Fi#+re 1.- Val"e $8 3in# 'ire !i n / /l 3

*F


55/124


S0mb l$ / r Me!alli an' N n5Me!alli ma!erial$

The symbols for metallic and non:metallic materials are contained in SA#S:,:& E +SS

S":' and AST+ specifications.

Fi#+re 11- S0mb l$ / r Me!alli ma!erial$

The following 6igure @* illustrates how a valve might be identified.

Fi#+re 12- Val"e i'en!i/i a!i n / r a #a!e "al"e


56/124


INSPECT VALVES

/t is the duty of the /nspector to verify that the proper material classification type andinstallation of valves are in accordance with Saudi Aramco standards industry standardsand pro5ect specifications. These standards are listed in the PApplicable StandardsVsection.

Since valves are one of the most critical elements in all Saudi Aramco plants the alve/nspector has a range of tas8s to perform. The valve will be inspected for one of thefollowing reasonsJ

/t is a new valve to be used in a critical service.

/t is a valve that has been rebuilt or repaired. (/ncludes the valves that have failed andis inspected to determine the cause of the failure and repairs re;uired. And valves re;uired of scheduled periodic inspection.)

Ne3 Val"e$ (Ven' r In$&e !i n)

The /nspector must verify that all valves are purchased from approved manufacturerslisted in SA#S:,:& '. Otherwise the vendors must undergo a plant survey and an

engineering evaluation of their products with respect to their capability of meeting Saudi Aramco specifications and applicable industry standards.

0o "urchase Orders shall be placed on any endor unless the endor has undergoneand passed this technical evaluation.

The /nspector should verify that the selection of valves is normally limited to thematerials types and siIes that are listed in SA+SS Class * unless no suitable valve islisted. /n this case proposed new valves must have a satisfactory in:serviceperformance history at two separate locations for at least two years each.

All vendors where new or approved shall implement and maintain an acceptable

Ruality "rogram e;uivalent to the /SO F Series which shall include clearly definedand documented procedures for the relevant Ruality Systems functions. The Ruality"rogram documents shall be made available to the 1uyerGs -epresentative for reviewand audit.

The /nspector conduct his wor8 by verifying that all valves are tested examined and;ualified as specified in the "urchase Order. The purchase order shall include relevantSA+SS. Testing and inspection shall comply with *:SA+SS: *E alve /nspection andTesting -e;uirements. Saudi Aramco /nspection -e;uirements 6orm &D : *@ &D :

&


57/124


*@ and &D : *@ & (See Addendum) must be attached to the "urchase Order.

Note: ome of the audi !ramco )aterial "stem pecification standards that cover valves are included in !ddendum !.

The /nspector shall verify that flanged ends have dimensions per the latest revisions of the standards listed in 6igure @ .

%p to '* inch AS+# ClassesJ AS+# 1& .

All SiIes A"/ A ClassesJ A"/ ST$ A

' inch to inch Class & -6J Std. $wg. A$: @ @*

' inch to inch Class @ -6J Std. $wg. A$: @ FF&

@ inch to *E inch Class * -6J Std. $wg. A$: @ FE

' inch to *E inch Class -6J Std. $wg. A$: @ D@' inch to *E inch Class @ -4J Std. $wg. AC: @ *E*

* inch to inch Class @ -4J Std. $wg. AC: @ *@D

' inch to *E inch Class -4J Std. $wg. AC: @ **'

Fi#+re 14- A&&li able $!an'ar'$ / r "al"e /lan#e' en'$

6langes other than those listed above shall comply with AS+# 1& .*D Series A unlessotherwise specified. -ing grooves shall comply with AS+# 1& .' . The gas8et contactsurface of all steel raised face flanges shall have a smooth machine finish in the range@.' to .* micrometers -A (-oughness Average).

/n case of welding the /nspector must verify that


58/124


6or cast steel valves (all siIes and ratings) the shell hydrostatic test shallconsist of three partsJ

a) A primary pressure:holding period of a minimum of @ minutes.

b) The reduction of the pressure to Iero.

c) The secondary pressure:holding period of a minimum of @ minutes.


59/124


Fi#+re 16- Val"e lea*a#e !e$!$ &er API 4:9-

*


60/124


61/124


Fi#+re 17- Val"e en' &r !e !i n re +iremen!$ (,.5SAMSS5;14)

The raised face portion of the flange and the ring 5oint groove shall be coveredwith heavy grease. A heavy:duty moisture:proof disc shall be fitted between thegreased flange face and the cover. The disc shall have a diameter e;uivalent tothe inside diameter of the bolt holes.

The ends of threaded and soc8et weld end valves shall be protected with tightfitting plastic caps.


62/124


Fiel' Te$!$

The valve shall be hydro:tested as per SA#S:,:& E and A"/: FE before it is installed in

the piping system. The field:testing includes the followingJ

Testing location shall be specified by proponent.

All new valves shall receive a body hydrostatic test prior to installation in theline.

All new valves designated for isolation service (as specified by the "roponent)shall be sub5ected to a high:pressure hydrostatic seat test prior to installation inthe line.

A low:pressure pneumatic seat test at @ 8"a ( psig) shall be substituted for the high:pressure hydrostatic seat test for flare system valves.

1uttweld and soc8etweld end valves in nominal pipe siIe (0"S) &: inch andsmaller are exempt from the above field:testing re;uirements.

Test procedures pressures durations and lea8age acceptance criteria shall bee;ual to those that the valves were originally purchased to.

Fiel' In$!alla!i n Limi!a!i n$

The /nspector shall be aware of the specific valve limitation on different types of valvesas listed in SA#S:,:& E.

/n addition gate valves with bac8 seats shall not be installed with their stems below thehoriIontal except in the following casesJ

Clean services


63/124


64/124


Spring:assisted non:slam piston chec8 valves (also referred to as noIIle chec8valves) shall be long:pattern with face:to:face dimensions in accordance with A"/S"#C $. Short:pattern valves shall not be used without the review andapproval of the Chairman of the alves Standards Committee.

Pl+# Val"e$ (@0'r arb n $er"i e nl0)

6langed plug valves in hydrocarbon service shall be of the inverted lubricated pressurebalanced design except that Class & valves 0"S inch and smaller may have astandard plug with springs for balancing the plug.

E i$!in# Val"e In$&e !i n

$uring visual inspection of existing valves it is the duty of the /nspector to examinevalves for lea8s through corrosion erosion crac8ing distortion bulging and other signsof deterioration or e;uipment failure. Other methods of inspection or testing are usuallyperformed as a result of a visual inspection.

An inspector should always use a good light source when ma8ing a visual inspection.Sources of good light areJ

A three:cell flashlight

& :watt lamp bulb with extension cord

-eflected sunlight from a mirror

2idden surfaces and otherwise difficult to reach areas can often be inspected by using amirror and a good light source.

Sa/e!0 '+rin# in$&e !i n

/n general before a valve is removed from the line that section of the line containing thevalve should be blan8ed from all sources of harmful li;uids gases or vapors. That

section of the line must be depressuriIed and purged of all oil toxic or flammable gasesand vapors.

All possible preparatory wor8 should be done before the scheduled start of inspection.The inspection tools needed should be chec8ed for availability proper wor8ing conditionand accuracy. #;uipment re;uired for personal safety should be chec8ed for availabilityand condition.

F


65/124


Reb+il! r re&aire' "al"e

A valve that failed is dismantled and inspected to determine the cause of the failure. The

valve is chec8ed for erosion corrosion and mechanical damage.

$uring scheduled periodic maintenance inspections valves in a critical service aredismantled to permit examination of all internal parts. 1ody thic8ness is measured atlocations that were inaccessible before dismantling. "articular attention is given tolocations that show evidence of corrosion or erosion. alves that operate in severe cyclictemperature service are chec8ed internally for crac8s. After reassembly the valve ishydro tested.

Fre +en!l0 O +rrin# Pr blem$


66/124


67/124


Fi#+re 1:- Sl+'#e a +m+la!i n l a!i n$ in a "al"e

Other problems that may cause a valve to be difficult to operate include corrosion of thevalve stem or stem threads and excessive tightening of the pac8ing gland bolts. Theseareas should always be chec8ed when operation problems occur. See 6igure * .

Fi#+re 2;- O!8er &r blema!i area$ in a "al"e

'


68/124


O!8er Pr blem$

A common reaction to a lea8y valve is to apply extra force in closing it but this maydamage the valve. 6or example a valve is lea8ing by the disc. /f additional force isapplied to stop the lea8age the disc and seat would be 5ammed together creatingexcessive pressure on the yo8e bushing and bonnet threads. 6orcing the valve closedcould cause galling of the valve seats.

+oreover if the valve were made of brass or any other soft metal forcing it closed couldnot only damage the seat and disc it could also cause the stem to be bent or the bonnetthreads to be stripped.

9enerally lea8ing from a valve may be of less concern if it is coming from the stem.

%sually change of the pac8ing is all what is re;uired.

,ea8age through the pac8ing gland is the most common type of valve lea8age. Thepac8ing inside the valve stuffing box is compressed by ad5usting the pac8ing gland torepair this type of lea8. /f ad5usting the pac8ing gland does not stop the lea8age thevalve must be re:pac8ed.

The stem should be inspected for damage. A bent or worn stem can cause lea8age eventhough the pac8ing is properly ad5usted. The stem can be inspected by opening andclosing the valve. The stem should be observed to see if it wobbles bac8 and forthwhich may be an indication that it is bent. On a rising stem valve it is important to loo8for signs of damage or corrosion when the valve is fully open. /f there is no apparent

damage the pac8ing should then be ad5usted.Seat lea8age may be caused byJ

/mproper seat interface.

Crac8ed seating surfaces.

/ncomplete valve closure.

Operator error.


69/124


#mbrittlement can occur when in the presence of a severe metal ductility loss due to in:service environments.


70/124


Fi#+re 2.- e'#e $ea!in# area in a #a!e "al"e

$ing chec valves can be inspected by removing the cover or cap. The seatingsurfaces on both the disc and the valve disc seat ring can be chec8ed for erosioncorrosion or mechanical damage by feeling them with your fingers. These inspectionareas are pointed out in 6igure *@.


71/124


Fi#+re 21- In$&e !i n area$ in a $3in# 8e * "al"e

The disc 6lapper should be chec8ed for freedom of rotation. The nut holding the discshould be chec8ed for security and the presence of a loc8ing pin loc8 washer or tac8weld. The arm should swing freely and the pivot pin should be inspected for wear. Theseinspection areas are pointed out in 6igure **.

Fi#+re 22- Di$ /la&&er in$&e !i n area$ in a 8e * "al"e


72/124


alve flanges should be visually inspected for distortion or dishing. 6lange faces shouldbe cleaned and inspected for evidence of corrosive attac8 or mechanical damage. Theseinspection areas are pointed out in 6igure * .

Fi#+re 24- Flan#e /a e$ in$&e !i n area$ in a #a!e "al"e

Globe valves are inspected in much the same way as gate valves as the inspector inspects the same parts of the valve. 2owever there are some differences between thegate valve and the globe valve that should be pointed out.

6igure * A shows a gate valve and 6igure * 1 shows a globe valve. /n a gate valve thefluid flow is in a straight line without bends. /n a globe valve the line of flow changesdirection.


73/124


Fi#+re 26- Fl 3 in a Ga!e an' Gl be "al"e$

The disc and seat arrangements are different between the gate and globe valve. 6igure*DA shows a gate valve disc and seat rings. 6igure *D1 shows a globe valve disc andseat ring.

The seats in a gate valve are perpendicular to the line of flow. The seat in a globe valveis parallel to the line of flow. 0ote also that the direction of flow through the globe valveis from below the disc. The globe valve should not be installed such that the fluid flow isfrom above the disc.

A gate valve has two seats while the globe valve has only one. /n a gate valve the disccome down between the two seats. /n a globe valve the disc comes down onto the seat./n a gate valve there is considerable wear between the disc and seats due to friction. /na globe valve there is very little wear between the disc and seat due to friction.


74/124


Fi#+re 27- Val"e $ea!$ in a Ga!e an' Gl be "al"e$

The disc on a globe valve is free to turn. ,i;uid flowing between the seat and disc willcause the disc to turn. 6igure *E shows the turning action of the disc in a globe valve.

1ecause of this turning action point A on the disc will not always contact point A on theseat ring. As a result the wear due to contact friction between the disc and seat ring ismore evenly distributed in a globe valve.

Fi#+re 29- T+rnin# a !i n / !8e 'i$ in a #l be "al"e

F


75/124


A$$+ran e Te$!$

After the valve has been repaired and reassembled it should be hydrostatically testedJ

-epairs that affect pressure:containing ability must be followed by a strength test of the valve body.

A seat test should be performed on valves re;uiring tight shutoff if the trim has beenrepaired or replaced.

A tightness (lea8) test shall be conducted at operating pressure after gas8ets and or pac8ing has been renewed.

Re r'$


76/124


Fi#+re 2:- A !0&i al In$&e !i n r*$8ee!

D&


77/124


Val"e all Re!iremen! T8i *ne$$

Over a period of time the valve body wall deteriorates due to erosion and corrosion.#ventually the wall thic8ness decreases to a minimum allowable thic8ness and at thistime the valve should be replaced. This minimum allowable thic8ness is referred to bySaudi Aramco inspectors as -etirement Thic8ness or Thic8ness +inimum. The twoterms have the same meaning and are abbreviated as (t m).

De!erminin# !8e !m / r Val"e$

Table & of A"/ specifies the t m values for steel gate valves. These tm values arespecified in inches. The same values are specified in metric increments in Table &A. The

inspector can read the minimum thic8ness from these tables for steel gate valves of any relevant siIe and rating.

6igure shows a portion of Table &. 6ind the tm for the shell wall of a &. :inch gatevalve with a @ :pound rating.

Fi#+re 4;- Par! / Table , (API 6;;)

D'


78/124


The shaded portions of 6igure & show that a & :inch steel gate valve with a @ :poundrating must have a minimum shell wall thic8ness of .D inches.

Fi#+re 4,- ! m 'e!ermina!i n / r "al"e$-

T8i *ne$$ Mea$+remen!

alve wall thic8ness is most often determined by %ltrasonic inspection methods (%T). Actual %T results are compared to the tm to determine if the valve will be safe to operateuntil the next scheduled Test and /nspection (T?/). The tm for pressure vessels pipeand valves is the absolute minimum wall thic8ness allowed for the e;uipment to remainin service. A valve must be repaired or replaced if at the current rate of deterioration itsthic8ness will be reduced below the tm before the next T?/.

/f corrosion or erosion is anticipated reference thic8ness measurements should bemade when valves are initially installed so that corrosion rate and metal loss can bedetermined.

D@


79/124



80/124

PEW-404.01 P ARTICIPANT EXERCISES

E ERCISE ,- IDENTIF% VALVES

This exercise will familiariIe you with the different types of valves used in the pipingsystems at Saudi Aramco. 6igure @ contains pictures of assorted valves. 6rom the listof valve types below label (with the valve type) the corresponding picture in 6igure @.

Val"e T0&e$

9ate

"lug

1all

1utterfly

9lobe

0eedle

$iaphragm

Angle

Automatic control

Chec8

D


81/124


Fi#+re 41- Di//eren! "al"e$ / r E er i$e ,

D


82/124


E ERCISE .- IDENTIF% P=ID VALVE S%MBOLS

This #xercise familiariIes you with the standard "iping and /nstrumentation $rawing("?/$) symbols used by the drafting department at Saudi Aramco. 6igure * is anassortment if "?/$ symbols. +atch the valve from the list to the corresponding "?/$symbol in 6igure *.


83/124


E ERCISE 1- IDENTIF% T@E MAIN PARTS OF A GATE VALVE

This #xercise familiariIes you with the main parts of a typical gate valve. 6igure is acut:away drawing of a gate valve. "lace the part number from 6igure next to thecorrect part name in the blan8s provided in the list below. #xampleJ 2and wheel is partnumber & and has been done for you.

Fi#+re 44- Par!$ / a #a!e "al"e / r E er i$e 1

DE


84/124


E ERCISE 2- IDENTIF% T@E MAIN PARTS OF A GLOBE VALVE

This #xercise familiariIes you with the main parts of a typical globe valve. 6igure shows a cut:away drawing of a globe valve. "lace the part number from 6igure nextto the correct part name in the list below.

Fi#+re 46- Par!$ / a #l be "al"e / r E er i$e 2

DF


85/124


86/124


Note: The ans$ers to this E2ercise must be supplied b" the &nstructor after he selectsthe specimen valve6s7 for measurement.

Fi#+re 47- O+!$i'e 'iame!er / /lan#e / r E er i$e 4

E&


87/124


E ERCISE 6- LOCATE SPECIFIC VALVES ON A PIPING ANDINSTRUMENTATION DRA ING

This #xercise gives you practice at locating specific valves on a "iping and/nstrumentation $rawing. 6igure E is a portion of a "?/$ for a $e:propaniIer. Arrowshave been drawn to point out certain valve symbols on the "?/$. /dentify the specifictype of valve by placing the correct name of the valve in the space provided ad5acent toeach arrow pointing to the valve symbol. 1e sure to include the normal operatingposition of the valve as indicated by the symbol.

Fi#+re 49- P=ID / r & r!i n / a 'e5&r &ani er / r E er i$e 6

E'


88/124


E ERCISE 7- INSPECT A DEFECTIVE VALVE

This #xercise gives you practice in the visual inspection of a defective valve. The/nstructor will demonstrate the correct procedure to inspect a gate valve. 9iven adefective gate valve the "articipant will perform an inspection of the valve determinethe defects in the valve and report the results of his inspection.

Tools -e;uired for This #xercise

/nspection tools as re;uired (see /nspection Tools list in


89/124


Chec8 the valve for ease of operation.

Chec8 the stem seats and gate for mechanical damage or corrosion erosion.

/nspect the gate:to:stem connection.

/nspect the guides on both gate and body for corrosion or erosion.

/nspect the valve body internally for corrosion or erosion.

Complete the following /nspection -eport -ecord the results of your inspection ma8erecommendations for corrective action.

In$&e !i n Re& r!

alveJ Type SiIe Class -atingYYYYYYYYYYYYYYYYY

6indingsJ

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY



-ecommendationsJ

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY



E*


90/124


E ERCISE 9- DETERMINE VALVE ALL T@IC


91/124


E ERCISE :- IDENTIF% MAR


92/124


E ERCISE ,;- OBTAIN A DRA ING OF A VALVE

A defective valve has been removed from plant 9DD for repair. The information on thevalve body is shown in 6igure . %se this information to obtain a drawing of the valve.%se


93/124

PEW-404.01 P ARTICIPANT WORKAIDS

OR< AID ,- TOOLS FOR INSPECTION OF VALVES

%,T-ASO0/C #R%/"+#0T

"O-TA1,# ,/92TS /0C,%$/09 6,AS2,/92T

T2/0:1,A$#$ 30/6#

SC-A"#-

/$ A0$ O$ T-A0S6#- CA,/"#-S

$/-#CT:-#A$/09 CA,/"#-S


94/124


OR< AID .- T%PES OF VALVES

Fi#+re 6,- T0&e$ / "al"e$

EF


95/124


OR< AID 1- PIPING AND INSTRUMENTATION DIAGRAMS%MBOLS

Fi#+re 6.- P=ID S0mb l$

F


96/124


OR< AID 2- DETERMINING TMHS FOR STEEL GATE VALVESSTEPS

&. $etermine the valve siIe i.e. W & W.

'. $etermine the pressure rating of the valve i.e. @ psig & psig.

@. ,oo8up tm in inches from Table & of A"/ . ,oo8up tm in millimeters if re;uired from Table & A of A"/ .

a. 6ind the valve siIe in the first column from the left. The column headingisJ

alve SiIe 0"S

b. +ove to the right in the row for the correct valve siIe to the column withthe subheadJ

S8ell all T8i *ne$$ under the correct heading for the pressure rating.

c. -ead the t m value from the table.

See the example belowJ t m Z .D inches for a & J : @ psig rated steel gate valve.

F&


97/124


F'


98/124


OR< AID 4- @O TO INSPECT A NE VALVE

+any new valves do not re;uire inspection. 2owever if the new valve will be used in acritical service then it should be inspected.


99/124


OR< AID 6- @O TO INSPECT A DEFECTIVE VALVE

Steps re;uired to determine the cause of failureJ

S!e&$

-eview the plant inspection log and e;uipment inspection record to determine thesymptoms of the valve failure.

-emove any temporary repair materials such as clamps bands plugs etc. in order to allow for a complete inspection of the valve.

/nspect the valve externally for any signs of corrosion or mechanical damage.

/nspect the flange faces for corrosion or mechanical damage.

/nspect the pac8ing gland nuts bolts and follower for corrosion.

Chec8 the ad5ustment of the pac8ing gland follower. /f the follower has been ad5ustednearly all the way down then additional pac8ing may be re;uired.

Chec8 the valve for ease of operation. /f the valve is difficult to operate then thepac8ing may need to be replaced.


100/124


OR< AID 7- @O TO INSPECT A REBUILT OR REPAIREDVALVE

S!e&$

/f parts have been replaced verify that the correct parts have been installed includingcorrect metallurgy.

+a8e sure that the valve trim material is correct for the type of service.

Note: The original trim material $ill be mar ed on the identification plate:

/nspect any weld build:up area of the valve body for ;uality of wor8manship andadherence to Saudi Aramco welding standards. Chec8 the built:up area for proper thic8nessusing a %.T. meter.


101/124


OR< AID 9- @O TO INSPECT VALVE DURING ASC@EDULED T = I

Certain valves are scheduled to be dismantled and inspected during the scheduled plantshutdown for a T?/.

S!e&$

-eview the plant inspection log e;uipment inspection records and T?l valve repair sheets for information on the history of the valve.

/nspect the valve externally for any signs of corrosion or mechanical damage.

/nspect the bonnet bolting for corrosion and proper length.

/nspect the flange faces for corrosion or mechanical damage.

/nspect the pac8ing gland nuts bolts and follower for corrosion.

Chec8 the ad5ustment of the pac8ing gland follower. /f the follower has been ad5ustednearly all the way down then additional pac8ing may be re;uired.

Chec8 the valve for ease of operation. /f the valve is difficult to operate then the

pac8ing may need to be replaced.


102/124


Fi#+re 61- Main &ar!$ / a /lan#e' #a!e "al"e

FD


103/124


Fi#+re 62- Main &ar!$ / a 3el'e'5en' #a!e "al"e

FE


104/124


OR< AID :- @O TO MEASURE VALVE BORE SI E ANDFLANGE SI E

This


105/124


106/124


107/124

PEW-404.01 P ARTICIPANT GLOSSARY

GLOSSAR%

a !+a! r The mechanical hydraulic electric or pneumatic device or mechanism used to open position or close a valve.

a+! ma!i n!r l The control of fluid flow or of a process variable by thecombined use of a valve actuator and sensing device.The valve is controlled in response to process changeswithout operator intervention.

ba */l 3 6luid or gas flow which is opposite to the direction of flowfor normal operation of the system process.

ba *$ea! A seat on the bonnet which contacts a correspondingseating surface of the stem when the stem is fullyretracted.

b '0 en' That portion of the valve body which is adapted for connection to piping

b '0 en' & r! The flow opening at the body end

b '0 /lan#e The flange on a valve body to which the bonnet or cover isbolted.

b '0 &l+# A threaded pipe plug designed to seal a tapped hole in thebody of a valve.

b '0 $ea! See seat

b l!e' b nne! A valve construction in which the bonnet is bolted to thevalve body.

b nne t A cover plate which is attached to the body by bolting.

b nne! A valve body closure component which contains an

opening for the stemb nne! b l!in# The bolting that secures the bonnet to the valve body.

b nne! /lan#e The flange on a bonnet through which the bonnet is boltedto the valve body.

b re The inside diameter of the body end port

& '


108/124


109/124


110/124


lea*


111/124


112/124


113/124


through the piping system.

(! ) !8r !!le To reduce or control the flow of fluid through a valve.

!i#8!5$8+!5 // (TSO) A complete shut:off of the flow without any lea8:through(passing) from the input port to the output port.

! i "oisonous to humans upon external or internal contact. Of or related to poison.

!rim 6unctional parts of a valve which are exposed to the linefluid. %sually refers to the stem closure member andseating surfaces

"al"e A device which isolates or controls fluid direction or flow

rate. SynonymsJ stop coc8 faucet tap."al"e b '0 The principal pressure containing shell of a valve which

has end ports adapted for piping

"al"e & r! The flow opening in a valve.

"al"e $!em !8r+$! The force re;uired to actuate a linear movement of a valvestem.

"al"e $!em ! r +e A tor;ue re;uired to actuate a rotary movement of thevalve stem.

3a/er "al"e A valve designed to be installed between flanges whichhas a short face:to:face dimension in relation to thepipeline diameter.

3e'#e A gate valve closure member whose seating surfaces areinclined to the direction of thrust so that can bemechanically forced into sealing contact.

3e'#e #a!e "al"e A gate valve design in which a wedge shaped closuremember is forced between angled seats to stop flow.

0 *e That part of a valve assembly used to position the stem nutor to mount the valve actuator.

& E


114/124


115/124

PEW-404.01 P ARTICIPANT ADDENDUM

*:SA+SS: & 9ate alve

This specification along with the purchase order defines the minimum re;uirements for steel bolted bonnet pressure seal bonnet flanged and butt:welding end gate valves of outside screw and yo8e (OS?7) construction. /ncluded are nominal pipe siIes (0"S) &through '* for Classes & through ' as covered by A"/ ST$ with the additionof the following siIesJ

' through inch Class &

' through *E inch Class @

' through *E inch Class *

' through *E inch Class

The valves covered by this specification shall be suitable for wet sour li;uid or gaseoushydrocarbon services with design temperatures between :&E and * NC.

*:SA+SS: ' 9lobe alves

This specification along with the purchase order defines the minimum re;uirements for steel bolted bonnet pressure seal bonnet flanged and butt:welding end globe angleglobe W7W pattern globe and globe stop chec8 valves of outside screw and yo8e (OS?7)construction in nominal pipe siIes (0"S) & and larger in Classes & through ' .

alves covered by this specification shall be suitable for wet sour li;uid or gaseous

hydrocarbon services with design temperatures between :&E and * NC.

*:SA+SS: @ Additional -e;uirements for ,ow Temperature alves

This specification along with the purchase order defines the minimum additionalre;uirements for steel valves in services with minimum design temperatures in the rangeof :&E deg C to :* deg C. All re;uirements as stated in the specifications attached tothe purchase order remain fully applicable except as modified herein.

*:SA+SS: Chec8 alves Swing Type

This specification together with the "urchase Order covers the minimum re;uirements

for steel bolted bonnet flanged and buttwelding end swing chec8 valves in ' inchesnominal pipe siIe (0"S) and larger for AS+# Classes & through ' .

alves covered by this specification shall be suitable for wet sour li;uid or gaseoushydrocarbon services with design temperature between :&E and * NC.

*:SA+SS: *& #xpanding "lug alve

This specification together with the "urchase Order covers the minimum re;uirements

&&


116/124


for steel double bloc8 and bleed non:lubricated plug valves with retracting soft seals(expanding plug valves) in nominal pipe siIe (0"S) ' through @ inch for AS+# Classes& through F .

alves covered by this specification shall be suitable for non:sour hydrocarbon servicesbetween temperatures of :&E and &' NC.

*:SA+SS: *' *:


117/124


*:SA+SS: ' 1all alves A"/ S"#C A

This Specification along with the "urchase Order covers the minimum re;uirements for

soft:seated flanged end trunnion:supported full bore ball valves in nominal siIes ':& &inches and above in A"/ S"#C A -ated


118/124


ADDENDUM B FORMS SA5,74

&&@


119/124

&&*


120/124

&&


121/124

&&


122/124

&&D


123/124


124/124

inspect valves (1)

Documents