PIPING MATERIAL SPECIFICATION
SHDHAKATE DATE : 24 Sep. 09
Selection of Piping material and preparation of PMS and VMS PMS is a Bible for a Piping Engineer. It consists all about material details, dimensional details, type of ends, schedules/thicknesses, branch offs, !" re#uirements, $arious codes / standards being follo%ed etc for all Piping items.
Inde& '. (eneral
). Specia Speciall re#uir re#uireme ements nts for for special special ser$ ser$ice icess * +esi +esist stan ance ce to ydr ydro ogen gen * +esis sistance to to Su Sulphur * +esi +esist stan ance ce to to Sou Sourr -ate -aterr Ser$ Ser$ic ices es * +esi +esist stan ance ce to aus austi ticc and and amin aminee . Engi Engine neeri ering ng Mate Materia rials ls * arbon St Steel * 0o% alloy steel * Stainless steels * Medium 1l 1lloys * igh 1lloys * ick ickel el and and nic nick kel allo alloy ys * opp opper er and and cop coppe perr all alloy oyss * "itanium * Plastic ma materials * +ubb +ubber er and and Elast lastom omer erss * omm ommon only ly used used mate materia rials ls in refi refine neri ries es
2. Materia Materiall Standa Standards rds and and spec specifi ificati cations ons
3. Prepar Preparatio ation n of of stand standard ard PMS / VMS VMS * * * *
-hat -hat a PMS PMS mea means ns and and -hat -hat doe doess it cons consist istss of. of. o% o% a pipi piping ng clas classs is is des desig igna nate ted d -hat -hat a VMS VMS cons consist istss and and ho% ho% a "1( "1( o o of VMS VMS is fi& fi&ed ed o% o% PMS PMS4V 4VMS MS for for a 5ob 5ob is prep prepar ared ed..
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1.0 General
Selection of materials of construction for piping is a $ery important acti$ity during the design stage of ydrocarbon Process Plants. "he primary ob5ecti$e in material selection is the achie$ement of the metallurgical stability to pre$ent failure resulting from en$ironment, normal operation and upset conditions. "he secondary ob5ecti$e is the achie$ement of design life by use of appropriate material of construction. Material selection for achie$ement of metallurgical stability shall be made on the basis of the design condition and to resist possible e&posures against fire, corrosion, operating condition, ser$ice etc. "he designer is confronted %ith the follo%ing concerns regarding the material of construction as he begins the design. "hese are * * * * * *
+esistance to stress +esistance to %ear !esign life +esistance to corrosion from process and atmospheric conditions. Economics +esistance to fire if re#uired.
"he first t%o concerns in$ol$es mechanical properties of materials such as tensile strength, yield strength, ductility fatigue strength, %ear resistance etc. !esign life for the piping is considered as '3 years. "he material deterioration due to corrosion is depend on se$eral factors such as operating conditions 6pressure and temperature7, process stream composition, phases, crack inducing agents upset conditions including steam flushing, ser$ice the system shall handle throughout the life time and its duration of operations etc. Medium handled occasionally like during shut do%n and re commissioning etc. shall also be considered. Effort shall be made to select material suiting %ell to the medium handled as %ell as the en$ironmental conditions. 1nd lastly Economics in Material Selection is also of $ital importance. In most instances there %ill be more than one alternati$e material %hich may be considered for a specific application. "he possibility of usages of inferior material materials %ith periodic replacement shall also be considered against the usage of superior material %ithout sacrificing the safety of the plant. alculation of true long term costs re#uires estimation of the follo%ings. * * * * * * * *
"otal cost of fabricated piping "otal installation cost Ser$ice life Maintenance cost, amount and timing ost of do%n time to replace or repair factors %hich impact ta&ation inflation rate Possibility of usage of inferior material
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2.0 Spe!"! Re#$!re%en& "'r Spe!al Ser(!e)* S'$r Ga)* +,-r'en* S$lp+$r* a%%'n!a a%!ne)* a$)&! )er(!e) e& Re)!)&ane &' H,-r'en
+esistance to hydrogen attack must be taken %hile selecting material in contact %ith li#uid and $apours containing hydrogen at ele$ated temperature and pressures. "he guide used for selecting hydrogen resistant material is 1PI publication 82' entitled 9Steel for ydrogen ser$ices at ele$ated temperatures and pressures in petroleum refineries and petrochemical plants. elson ur$es 1 brief Study of elson ur$es on the follo%ing re$eals that the principle alloying elements %hich impart resistance to ele$ated temperature hydrogen attack are chromium and molybdenum. 1lloy steel commonly used to resist high temperature hydrogen attack are as follo%s * * '/) Mo * ' *'/2 : ; Mo * 3r : ; Mo * 8r : ' Mo * '<r, ')i, )M=
P' P'' P3 P8 SS '<
Re)!)&ane &' S$lp+$r
>or determining materials of construction for an oil stream containing sulphur utilisation the cur$e entitled 91$erage +ate for igh "emperature Sulphur orrosion? "his cur$e aids in determining corrosion rates for materials in contact %ith Sulphur bearing ydrocarbon streams and is used primarily for crude, $acuum, $is * breaker asphalt o&idising units and ra% oil charge lines to hydro de sulphuring and hydro* cracking units. -hile applying this cur$e, use the ma&imum operating temperature of the e#uipment in$ol$ed and pick the corresponding corrosion rate for one of the materials listed then ad5ust the corrosion rate %ith a correction factor %hich takes into account the %eight percent sulphur. It should e noted that the reference sulphur le$el for this cur$e is '.= %eight percent. 1s one can see from this cur$e, an increase in chromium content imparts increasing resistance to high temperature sulphur corrosion. arbon Steel is generally specified for most e#uipment to )<= : )@@ deg temperature range, and the corrosion allo%ance used is mm. -hen the piping in thid ser$ice are carbon steel, and impro$e corrosion resistance is necessary, "P 2'= S stainless steel cladding is specified. !epending on the anticipated corrosion rates
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heater tubes usually 3 r : ; Mo or 8 r : 'Mo . Piping systems are usually arbon steel and 3r : ; Mo %ith $arying corrosion allo%ances.
Re)!)&ane &' S'$r /a&er Ser(!e) H2S
* * * *
* *
Material shall be selected from those permitted I the 1E standard. Selection of material should be for a specific sour duty condition. If process )S concentration is $arying , peak $alues shall be used. "he resistance to general corrosion . "he P $alue of the process stream and the presence / absence of corrodents such as o&ygen , A), chlorides etc are particular importance Mechanical Properties including lo% temp re#uirements %here necessary shall be gi$en special attention. arbon Steel shall be in the normalised heat treated conditions.
Re)!)&ane &' Ca$)&! an- A%!ne
arbon Steel is generally used and is acceptable material for handling caustic soda and other alkaline solutions. o%e$er it has limitations. igher temperature in that stress corrosion cracking can occur unless it is stress relie$ed , also unaccepted general corrosion can take place. >or amine ser$ices to a$oid stress corrosion cracking of %elded pipes and other %elds, e&posed to $arious amine solutions, stress relie$ing for all %elds is re#uired as follo%s * ME1 >or all design temperature * !E1 >or design temperature @) deg * >or additional guidance for a$oiding corrosion of stress corrosion cracking S can be referred in 1PI 823.
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.0 En!neer!n Ma&er!al)
'.= Metallic : >errous, on*>errous ).= on*Metallic : Arganic , Inorganic .= omposites >errous : arbon Steel, 0o% 1lloy Steels, Stainless Steels, Medium 1lloys, igh alloys, ast Iron. on*>errous : ickel, Monel, Brasses, BronCes, upro*nickels. Arganic : Plastics, "hermo*Plastics, "hermo*settings, Elastomers Inorganic : eramics, (raphite, (lass, +efractories. Most commonly used materials in refineries are arbon Steel, 1lloy Steels, and Stainless Steels, brief description of the materials are as follo%s 1.0 Car3'n S&eel) "his is the most common and cheapest material used in process plants. arbon steels are used in most refinery applications. It is routinely used for most organic chemicals and neutral or basic solutions at moderate temperatures. arbon steels are e&tensi$ely used in temperature range of *)8 deg to 2)D deg . 0o% temperature arbon Steel 60"S7 can be used to a lo% temperature of *2< deg . illed carbon steel are defined as those %hich are thoroughly deo&idiCed during melting process. !eo&idation is accomplished by use of silicon, manganese and aluminium additions to combine %ith dissol$ed gases, usually o&ygen, during steel making. "his results in cleaner better #uality steel %hich has fe%er gas pockets and inclusions. illed carbon steel is specified for ma5or e#uipment in the follo%ing ser$ices to minimise the possibility or e&tent of hydrogen blistering and hydrogen embrittlement
* *
-here hydrogen is a ma5or component in the process stream. -here hydrogen sulphide )S is present %ith an a#ueous phase or %here li#uid %ater containing )S is present. * Process streams containing any amount of ydro flouoric 1cid > , boron trifluoride B> or B> compounds * Monoethanolamine ME1 and !iethanolamine !E1 in solutions of greater than 3 %eight percent. 2.0 L' All', S&eel 0o% 1lloy Steel contain one or more alloying elements to impro$e mechanical or corrosion resisting properties of carbon steel. ickel increased toughness and impro$es lo% temperature properties and corrosion resistance. hromium and silicon impro$e hardness, abrasion resistance, corrosion resistance and resistance to o&idation. Molybdenum pro$ides strength at ele$ated temperatures. Some of the lo% alloy steels are listed belo%.
'.= arbon*'/).F Moly and Manganese : ;F Moly G "hese lo% alloy steels are used for higher temperature ser$ices and most fre#uently for intermediate temperatures for its resistance to hydrogen attack. "hey ha$e the same ma&imum
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temperature limitation as killed steel 6 1SME ode : '=== deg > 7 but the strength abo$e D== deg > is substantially greater. ).= 'F hrome : ;F Moly and ' : HF hrome : ; FMoly G "hese alloys are used for higher resistance to hydrogen attack and sulphur corrosion. "he are also used for ser$ices %here temperatures are abo$e the rated temperature of * ; Mo Steel. .= )*'/2 hrome : 'FMoly and 3hrome : 'FMoly G "hese alloys ha$e the same uses as '*'/2 r, but ha$e greater resistance to hydrogen attack and ha$e higher strength at ele$ated temperature. 2.= 3Fr* ;FMoly G "his alloy is used most fre#uently for protection against combined sulphur attack at temperature abo$e 33= deg >. Its resistance to hydrogen attack is better than )*'/2r : 'F Mo. 3.= 8Fhrome : 'FMoly G "his alloy is generally limited to heater tubes. It has higher resistance to sulphur stocks at ele$ated temperatures. It has a ma&imum allo%able metal temperature in o&idising atmospheres. .0 S&a!nle)) S&eel)
"hey are heat and corrosion resistance, non*contaminating and easily fabricated into comple& shapes. "hese are three groups of stainless steels, $iC, Martensitic, >erritic and 1ustenitic. i7 Martensitic Stainless Steel G Martensitic 1lloys contain ') : )= percent chromium %ith controlled amount of carbon and other additi$es. "ype 2'= is a typical member of this group. "hese alloys can be hardened by heat treatment, %hich can increase tensile strength. orrosion resistance is inferior to 1ustenitic stainless steels and these are generally used in mild corrosi$e en$ironments. ii7 >erritic Stainless steels G >erritic steels contain '3 : = percent chromium %ith lo% carbon content 6 =.'F7. igher chromium content impro$es its corrosi$e resistance. "ypical member of this group is "ype 2=. "he strength of these can be increased by cold %orking but not by heat treatment. "ype 2= is %idely used in nitric acid plants. In addition , it is $ery resistant to scaling and high temp o&idation up to @== deg iii7 1ustenitic Stainless Steel G 1ustenitic steels are the most corrosion resistance of the three groups. "hese steels contain '< : )< percent chromium, < : )) percent ickel arbon is kept lo% 6 =.=@F ma&7. to minimise carbide precipitation. -elding may cause chromium carbide precipitation, %hich deplete the alloy of some chromium and lo%ers its corrosion resistance in some specific en$ironments. otably in nitric acid. "he carbide precipitation can be eliminated by heat treatment 6solution annealing7. "o a$oid precipitation special steels stabiliCed %ith titanium, niobium, or tantalum ha$e been de$eloped 6"ype )', 2D , 2@7, 1nother approach to the problem is to use the lo% carbon stainless steels such as types =20 and '<0 %ith =.F ma& carbon. "he addition of molybdenum to austenitic alloy types '<, '<0 pro$ides generally better corrosion resistance and impro$ed resistance to pitting.
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"he chromium nickel steels , particularly the '@*@ alloys, perform the best under o&idising conditions, since the resistance depends on an o&ide film on the surface of the alloy. +educing conditions and chloride ions destroy this and bring on the rapid attack. hloride ions tend to cause pitting and cre$ice corrosion. -hen combined %ith higher tensile stresses, they can cause stress corrosion cracking. 4.0 Me-!$% All',)
1 group of mostly proprietary alloys %ith some%hat better corrosion resistance than stainless steels are called medium alloys. 1 popular member of this group is 20 all',. Made by a number of companies under $arious trade names. !urinet )=, arpenter )= are a fe% names. "his alloy %as originally de$eloped to fulfil the need for a material %ith sulphuric resistance superior to stainless steels. Ather members of this group are Incoloy @)3 and astelloy (*. "hese alloys ha$e e&tensi$e application in sulphuric acid systems. Because of their increased nickel and moly contents they are more tolerant of chloride ion contamination than standard stainless steel. "he nickel content decreases the risk of stress corrosion cracking and molybdenum impro$es resistance to cre$ice corrosion and pitting. 5.0 H!+ All',)
"his group of materials called high alloys all contain relati$ely large percentage of ickel. astelloy B) contains <'F ickel and )@FMo. "he alloy has unusually $ery igh resistance to all concentrations of l at all temperatures in the absence of o&idiCing agents. Ather material of this group are hlorimet and astelloy *)D<. 6.0 N!7el an- N!7el All',)
"he metal is %idely used for handling alkalies particularly in handling and storing caustic soda. eutral alkaline solutions, sea%ater, and mild atmospheric conditions do not affect nickel. 1 large number of nickel based alloys are commercially a$ailable. Ane of the best kno%n out of these is Monel 2== %ith
8.0 C'pper an- 'pper All',)
opper and its alloys are %idely used in chemical processing, particularly %hen heat and thermal conducti$ity is $ery important. Main copper alloys are Brasses 6u*Jn7, BronCes 6 u*Sn7 and uproickels. Some of the BronCes are $ery popular in process industries. 0ike allumunium and silicon bronCes because they combine good strength %ith corrosion resistance. upronickels ha$e '=*= F nickel and ha$e become $ery popular because it has the highest corrosion resistance of all copper alloys. "his finds its application in heat e&changer tubing and its resistance to sea %ater is especially outstanding.
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.0 T!&an!
%$"itanium has become increasingly important as a construction material. It is strong and of medium %eight. orrosion resistance is $ery superior in o&idiCing and mild reducing media. "itanium is usually not bothered by impingement attack, cre$ice corrosion, and pitting attack in sea %ater. Its general resistance to sea %ater is e&cellent. 9.0 Pla)&! Ma&er!al)
In comparison %ith metallic materials, the use of plastic is limited to relati$ely moderate temperatures and pressures 6)= deg is considered high for plastic7. Plastics are also less resistant to mechanical abuse and ha$e high e&pansion rates, lo% strength,6thermoplastics7 and only fair resistance to sol$ents. o%e$er they are light%eights are good thermal and electric insulators are easy to fabricate and install, ha$e lo% friction factors. Since plastics do not corrode in the electrochemical sense, they offer another ad$antage o$er metals. "he important thermoplastics used commercially are polyethylene, poly$inyl chloride, florocarbons 6"eflons, alar, el*>, kynar7 and polypropylene. Important thermosetting plastics are general purpose polyester glass reinforced, bisphenol based polyester glass, epo&y glass, $inar ester glass, furan and phenolic glass, and asbestos reinforced. -hile using non metallic piping $iC, !PE, PV , >+P etc the designer shall take care of the ser$ice, pressure and temperature. Manufacturer?s recommendation shall be taken into account. 10.0 T+er%'pla)&!)
"he most chemical resistant plastic commercially a$ailable today is tetrafluoroethylene or ">E. "his thermoplastic is practically unaffected by all alkalies and acids e&cept fluorine and chlorine gas at ele$ated temperature and molten metals. It retains its properties up to )<= deg Perfluoroalkok&y or P>1 has the general properties and chemical resistance of >EP at a temperature approaching == deg Polyethylene is the lo%est cost plastic commercially a$ailable. Mechanical properties are generally poor, particularly abo$e 3= deg and pipe must be fully supported. arbon filled grades are resistant to sunlight and %eathering. Polypropylene has chemical resistance about the same as that of polyethylene, but it can be used at ')= deg . 11.0 T+er%')e&&!n Pla)&!)
1mong the thermosetting materials are phenolic plastics filled %ith asbestos, carbon, or graphite glass or silica. +elati$ely lo% cost, good mechanical properties, and chemical resistance e&cept against strong alkalies, make phenolics popular for chemical e#uipment. >uran plastics filled %ith asbestos and glass ha$e much better alkali resistance than phonolic resins. Polyester resins reinforced %ith fibreglass, ha$e
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good strength and good mechanical resistance e&cept alkalies. Epo&ies reinforced %ith fibreglass ha$e $ery high strength and resistance to heat. "he chemical resistance of the epo&y resin is e&cellent in non o&idiCing and %eak acids but not good against strong acids. 1lkaline resistance is e&cellent in %eak solutions. 12.0 R$33er an- ela)&'%er)
+ubber and elastomers are %idely used as lining materials. "he ability to bond natural rubber to itself and to steel makes it ideal for lining tanks. Na&$ral r$33er is resistant to dilute mineral acids alkalies and salts but o&idiCing media, oils and most organic sol$ents %ill attack it. Har- r$33er is made by adding ) percent or ore of sulphur to natural or synthetic rubber an as such is both hard and strong. C+l'"'prene 'r ne'prene r$33er is resistant to attack by oCone , sunlight, oils gasoline and aromatic or hyfrogeneted sol$ents but is easily permeated by %ater thus limiting its use as a tank lining. N!&r!le r$33er is kno%n for resistant to oils and sol$ents. $&,l r$33er is kno%n for resistant to dilute mineral acids and alkalies . hypalon has outstanding resistance to oCone and o&idiCing agents e&cept fuming nitric and sulphuric acids. >luoroelastomers Viton*1, el*>, alreC combine e&cellent chemical and temperature resistance. "he commonly used 1S"M materials are as gi$en in separate sheet.
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4.0 Ma&er!al S&an-ar-) an- Spe!"!a&!'n)
1t this point let us understand the need of standard materials and specifications. "here are some consensus standards %hich defines the chemistry and properties of specific materials. Such standards allo% the designers and users of material to %ork %ith confidence that the materials supplied %ill ha$e the e&pected minimum properties. !esigners and users can also e confident that comparable materials can be purchased from se$eral suppliers. Producers are confident that materials produced to an accepted standard %ill find a ready market. 1 fe% of the organiCations %hich generate standards of ma5or importance to chemical : process industry are as listed belo% G *
1ME+I1 1"IA10 S"1!1+!S IS"I"K"E 6 1SI7,It promulgates the Piping codes used in hemical Process Industries * 1ME+I1 SAIE"L A> ME1I10 E(IEE+S 61SME7 G "his society generate the Boiler and Pressure Vessel code. * 1ME+I1 SAIE"L >A+ "ES"I( 1! M1"E+I10S61S"M7 G "his society generates specifications for most of the materials used in the 1SI piping codes and 1SME Boiler and Pressure Vessel codes. * Ather codes follo%ed are BS, !I, IS etc. 1.0 Prepara&!'n '" S&an-ar- PMS ;
Before going for this it has to be understood : -hat a PMS means and %hat does it consist of 4 o% do %e designate PMS 4 -hat a VMS consists and its "ag o. /+a& a PMS %ean) an- +a& -'e) 'n)!)&) '" PMS is a Bible for a Piping Engineer. It consists all about material details, dimensional details, type of ends, schedules/thicknesses, branch offs, !" re#uirements, $arious codes/standards being follo%ed etc for all Piping items. Main Piping items detailed out in PMS are listed belo%
* * * * * * *
Pipes >ittings >langes Bolts (askets Val$es Misc Items like Steam traps and strainers
1 short description of piping items is listed belo% '.= Pipes G "ypes : Seamless, %elded E >S -, E + -
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Ends : PE for ' ;N BE for O )N Schedule/thickness G alculation of proper thickness is a must Because lesser thickness may lead to pipe failure and more thickness may cause fle&ibility and support problems, may re#uire hea$y structure and %ill lead to high cost of the plant. "hickness is calculated as per : 1SI B '. for Process Piping and IB+ for steam / boiler feed %ater under IB+ scope. "he calculated thickness shall cake care of orrosion and other allo%ances and manufacturer?s tolerance "he thickness thus calculated is rounded off to ne&t higher commercially a$ailable thickness. "o reduce in$entory and for inter*changeability certain schedules are preferred. >or siCes O ' ;N )N and abo$e
G S@=, S'<= QQS G S"! , QS
>or siCes beyond certain limit usually 'or carbon and lo% alloy pipes 1SME/1SI B<.'8 G >or SS pipes
).= >ittings G "ypes : Elbo%s, "ees, aps, ouplings, -eldolets, Sockolets, Elbolets, rosses, +educers etc. "hickness G corresponding pipe
>or B- fittings the end thickness is same as that of
>or scre%ed / S- fittings, 1SI rating ===R, <===R and 8===R are used. "his standardiCation is done to reduce the $ariety of small dia fittings Ends G ormally end connections are * for '*'/)N S- and for )N and abo$e BB- ends confirm to 1SME B '<.)3 -eld ontour Preperation !imensions G B- fillings * 1SI B '<.8 / MSS SP 2@ S- fittings : 1SI B '<.'' .= >langes : >langes pro$ide a bolted, separable 5oint in piping. -hen to flanges G * -here there is a clear need for remo$al of $al$es or e#uipment, for access of maintenance, or for blinding. * Because all flanged connections are potential leak source, their use is should be kept to minimum needed for safe and reasonably con$enient operation and maintenance.
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*
Beyond lass <==, the use of flanges in all ser$ices is further limited because of high potential of leaks.
Industry Standards : 1SME B '<.3 1SME B'<.2D 1 6MSS SP 227
;N to )2N lass '3=R to '3==R ;N to ')N lass )3==R )
1SME B '<.2D B 61PI <=37
)
"ype of >langes * -eld eck 6-7 Strongest connection because of full penetration butt %eld. * Socket -eld 6S-7 ommonly used for ;N to * ;N , may not be acceptable for ser$ices %here cre$ice corrosion can occur. * Slip An 6SA7 More economical, acceptable for undemanding ser$ices if it is %elded on both the inside and outside, ot acceptable for high temp/cyclic ser$ices * 0ap Toint 60T7 Kses a lap 5oint stub end on the pipe and a flange that rotates freely, easy field alignment of bolt holes, >lange can be of cheaper metallurgy, ot suitable for cyclic / $ibrating ser$ices >lange >acing : "he common flange facings are * * *
>lat >ace 6>>7 is normally used only on cast iron flanges or steel flanges that mate to cast flanges and re#uires full face gasket +aised >ace 6+>7 is the most commonly flange facing +ing "ype Toint 6+"T7 is used for high pressure, high temperature ser$ices 6lass 8==R and abo$e7
Surface >inish for >langes * "he re#uired surface finish of the gasket contact area on the flange is determined by the type of the gasket used. * on*metallic gaskets pro$ide a good sealing e$en %ith a relati$e rough surface finish 63== micron in 11+7 * Spiral %ound gasket for flanges re#uire ')3 to )3= micron in 11+ finish * +ing 5oint re#uires a finish no rougher than < micron in 11+ finish on the contact of the groo$es and gaskets BA0"S * * *
* *
hoice of bolting material is go$erned by ser$ice fluid and the temperature "he most commonly used bolts for flanges in the refinery piping are 1S"M 1 '8 (+ BD Stud bolts %hich fall into the high strength group. "he temperature range is from *)8 deg to 232 deg "he medium strength 1SM" 1 '8 (+ BDM studs are re#uired in some ser$ices to a$oid sulphide stress corrosion cracking. 0o% carbon machine bolts as per 1S"M 1 =D (+ B are in the lo% strength group. "hey should be used for all cast iron flanges, to pre$ent
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the o$erstressing the flanges and for class '3= upto '
(1SE"S Since it e&pensi$e to grind and lap 5oint faces to obtain fluid*tight 5oints, a gasket of some softer material usually is inserted bet%een contact faces. "ightening of bolts causes the gasket material to flo% into the minor machining imperfections, resulting in a fluid tight seal. "ypes * Soft gaskets like cork, rubber or asbestos * Semi metallic design G it combines metal and a soft material, the metal to %ithstand the pressure and temp and the soft material to impart resilience. * Various modified designs and cross*sectional shapes Standards G * 1SME B'<.)= G Metallic (askets for Pipe >langes, +ing Toint, Spiral -ound and Tacketed * 1SME B '<.)' G on Metallic >lat (askets for Pipe >langes * IS*)D') G different (rades >ollo%ing important points shall also be taken care of in case of gaskets * ardness of gaskets for +"T flanges G ardness of +"T gasket shall be )= B less than the corresponding flange groo$e hardness * Kse of inner and outer ring for Spiral -ound (asket G (enerally inner gasket shall be used to pro$ide as per the follo%ing re#uirement * 1s per code re#uirements B'<.)= * >or siCes )or $acuum, hydrogen, and cryo ser$ices * >or SS)',SS2D and grade SS classes * >or 8==R rating and abo$e classes * >or classed %here temp is 2)D deg * +estrictions in use of asbestos %hich other%ise is an e&cellent sealing material.
MIS. I"EMS '. Steam "raps G Steam traps are used to retain steam in a heating unit or in piping until it has condensed and gi$en up its latent heat , the condensate and air are then discharged by the trap either to atmosphere or back to the boiler or to the condensate tank ). Strainers : "ypes G "emporary onical type
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G Permanent " type, L type
V10VES '. Various type of $al$es used are as follo%s a. (ate b. (lobe c. heck d. Ball e. Plug f. Butterfly g. !iaphragm h. eedle i. Blo% !o%n 5. Piston type $al$es etc ). >unction %ise the abo$e mentioned $al$es can be categoriCed as follo%s a. An*off Val$es G (ate, Ball, Plug, Butterfly, !iaphragm b. >lo%*+egulations G (lobe, Butterfly c. on*return $al$es G heck $al$es d. Sample Val$es G eedle $al$es . !esign and "esting Standard of $al$es a. (ate )N 1PI*<=) O )N 1PI*<== b. (lobe )N BS 33) O)N BS '@D c. heck )N BS 33) O)N BS '@<@ d. Ball BS 33'/1PI
1PI*38@ 1PI*38@ BS
Ather !esign as %ellas "esting Standards are 1SME B '<.2, BS '2'2 E" 2. !imension Standard G 1SME/1SI B '<.'=, BS )=@=
3. A- 1 PIPI( 01SS IS !ESI(1"E!. It is base on the philosophy of indi$idual consultant In EI0 It is of digit like 1'1 * the first letter indicates the pressure rating, 1: '3=R, B* ===R, * 2==R, !*<==R, E*8==R, >*'3==R, (*)3==R, T*')3/'3=R, * K01SSI>IE! * the middle letter indicates the difference in the specification %ithin the same rating and material
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*
"he third letter indicates the type of material, 1*arbon, B*arbon Moly, U different alloy steels, * stainless steels=2.,0 M* Stainless steels '<,,)',2D
In 0inde it is a of < digit like 01'+<' * the first letter Tob letter * the second letter is material code * third letter is pressure rating * the forth letter is >lange >acing * the fifth letter is se#uential number 6<' on%ards7 <. -1" 1 VMS ASIS"S 1! A- 1 "1( KMBE+ A> VMS >IQE! "his specification consists of all the $al$e specification sheets %hich contain complete detail about each $al$e like material of $arious components of a $al$e , dimension standards, testing standards etc "he tag number is base on indi$idual consultant. In EI0 it of 3 digit numer * the first t%o digits indicates the type of $al$es like 3' for gate * the third digit indicates the pressure rating, * last t%o digits indicates $al$e metallurgy / ser$ice like =' : )3 G arbon steel, )<*22 G 1lloy steel, 23*D2 G stainless steel etc
D. A- PMS / VMS >A+ 1 TAB 1+E P+EP1+E! !epending upon the $arious parameters like temperature, pressure, corrosion allo%ance, fluid ser$ice etc and years of e&perience, Standard PMS ha$e been prepared in consultation %ith Process and Metallurgies. "hese standard PMS/VMS are stored in the Piping package. "he 5ob Engineer collects a list of all the PMS specs re#uired in the 5ob from the process engineer/process PI!. 1ll the PMS specs re#uired of the Tob is then copied from Standard PMS, An the basis of Tob specific re#uirements of 0icensor/lient, the re#uired changes are then made by the Tob Engineer in the PMS to get the TAB PMS. >or TAB VMS all the $al$e specs sheets co$ered in the TAB PMS are copied from Standard VMS and once again on the basis of Tob Specific re#uirements by 0icensor/lient re#uired changes are made by the TAB Engineer in the VMS to get the TAB VMS.
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