PR VESSEL docuement

7/24/2019 PR VESSEL docuement

1/129

IndianOil

M&I Deptt., Ref. Div. Indian Oil Corporation Limited

Pressure Vessel Manual, Rev.-1, Nov. !"

COVER PAGE

Pa#e 1 of 1$%


2/129

IndianOil



INSPECTION MANUAL FOR UNFIRED PRESSURE VESSELS

INDEX

Sl. No. Topics Page No.

1.0 PRESSURE VESSEL

1.1 COP'

1.$ D'(INI)ION

1." )*P' O( PR'+R' V''L

1. N'C'I)* O( INP'C)ION

1. )*P' O( INP'C)ION

1. )OOL R'/+IR'D (OR INP'C)ION O(PR'+R' V''L

1.0 (R'/+'NC* O( INP'C)ION

.0 SUPPLEMENTAR! SPECIFICATION FOR CLADDEDPRESSURE VESSELS

$.1 COP'

$.$ D'IN

$." M2)'RI2L

$. (23RIC2)ION

$. 4'LDIN

$. INP'C)ION

$.0 5'2) )R'2)M'N)

$.6 +R(2C' CL'2NIN

$.% )')IN

".0 PRESSURE VESSELS IN T#E SERVICE OF#!DROGEN$ #!DROGEN SULFIDE$ SOURSERVICES ETC.

".1 R'/+IR'M'N) (OR 5*DRO'N 'RVIC'

".$ R'/+IR'M'N) (OR +L(+R CORROION

"." R'/+IR'M'N) IN O+R 'RVIC'

". R'/+IR'M'N) (OR C2)2L*)IC R'(ORM'R2ND 5*DRO-D'-+L(+RI7'R

". P'CI(IC CONDI)ION 45'R' PO)4'LD 5'2))R'2)M'N) I R'/+IR'D

%.0 DESIGN P#ILOSOP#! OF TALL COLUMNS

&.0 C#EC' LIST FOR INSPECTION OF PRESSUREVESSELS PRIOR TO ERECTION ANDCOMMISSIONING

.1 LI8'L* LOC2)ION O( M')2L 42)2'

.1.1 Main (ra9tionin# )o:ers of Crude Distillation +nit

.1.$ Crude Distillation +nit Over;ead 299umulators

.1." De;


3/129

IndianOil



.1. Rea9tors in Reformers

.1. Rea9tors in (CC+

.1.0 Re#eneration in (CC+

.1.6 Orifi9e C;am>er in (CC+

.1.% Co?e C;am>ers

.1.1! 3ullets and p;eres.1.11 Vessels in Lo: )emperature ervi9e

.1.1$ 2mmonia tora#e Vessels

.1.1" Columns & Vessels in Diet;


4/129

IndianOil



10.0 PRESERVATION OF E)UIPMENT

1!.1 IDL' )IM' PR''RV2)ION O( COL+MN 2NDV''L 2 P'R OID-101

1!.1.1 Introdu9tion

1!.1.$ 9ope

1!.1." Definitions1!.1. Consideration for sele9tion of Prote9tive


5/129

IndianOil



Pa#e of 1$%


6/129

IndianOil



1.0 PRESSURE VESSELS

1.1 SCOPE

);is manual 9overs t;e minimum inspe9tion reAuirements for unfired

pressure vessels mainl< 9olumns and vessels. );e manual spe9ifiesmainl< on t;e met;ods of inspe9tion and areas to >e inspe9tion int;ese pressure vessels.

1. DEFINITIONS

Pess2e Vessel

2 pressure vessel is usuall< defined as a vessel desi#ned to safele su>e9ted to eBternal pressure 9aused >< an internalva9uum or >< a fluid pressure >et:een an outer a9?et and t;e vessel:all. u9; vessels are usuall< inspe9ted in t;e same manner asvessels :it; internal pressure.

Pressure of ea9; vessel s;all >e spe9ified in t;e follo:in# manner

Opea3i4g pess2e

MaBimum pressure li?el< to o99ur an< time durin# t;e lift of t;e vessel.);e most severe 9onditions of 9oin9ident pressure and temperature

s;all >e determined not onl< for normal operation >ut also durin# start-up, s;utdo:n, re#eneration, de9o?in# et9. );is :ill involve9onsideration of sour9e relief valve settin#, pump s;ut off ;ead andstati9 ;ead separatel< or in 9om>ination, to#et;er :it; ot;er se eAual to operatin# pressure plust 1!GEminimum 1?#= 9m$F

E>F 4;en operatin# pressure is over 0!?#= 9m$.Desi#n pressure s;all >e eAual to operatin# pressure plus GEminimum 1?#= 9m$F.

E9F Desi#n pressure 9al9ulated a>ove s;all >e at t;e top of verti9alvessel or at ;e ;i#;est point of ;ori@ontal vessel and s;all not >eless t;an ".?#= 9m$.

EdF );e desi#n pressure at an< lo:er point is to >e determined >e added to >ot; sides of tra< supportrin#s and ot;er fiBed internal non pressure parts, :;en eBposed to9orrosive liAuid or vapour.

Remova>le internal parts E:it; t;e eB9eption of traolted

or 9lamped in pla9e, s;all >e provided :it; eBtra t;i9?ness eAual to ;alft;e spe9ified 9orrosion allo:an9e on ea9; surfa9e eBposed to vessel9ontents.

On fillet and seal :elds on internal atta9;ments, full 9orrosionallo:an9e s;all >e added to t;e t;roat t;i9?ness ne9essar< for stren#t;or sealin#.

);e 9orrosion allo:an9e for no@@les and man;oles s;all >e at leasteAual to t;at spe9ified for vessel s;ell= ;ead.

(or allo< lined or 9lad vessels, no 9orrosion allo:an9e is reAuired ont;e >ase metal. );e 9laddin# or linin# material Ein no 9ase less t;an1.mm t;i9?nessF s;all >e 9onsidered as 9orrosion allo:an9e.

Claddin# or linin# t;i9?ness s;all not >e in9luded in stren#t;9al9ulations.

*i47 co4si7ea3io4

4ind load s;all >e 9al9ulated on t;e follo:in# >asis

EaF Indian tandard J I 60 Elatest editionFE>F Minimum dra# 9oeffi9ient for 9e !.0.

Ea3892a:e co4si7ea3io4

'art;Aua?e for9es s;all >e 9al9ulated in a99ordan9e :it; Indiantandard I 16%"= spe9ifi9 spe9tra developed for parti9ular site. 5i#;eart;Aua?e prone @ones s;all merit spe9ial 9onsideration. 4ind andeart;Aua?e s;all not >e ta?en to a9t simultaneousle as #iven>elo:

EaF (or 9ar>on, lo: alloF tainless steel vessels J mm.E9F (or 9ar>on, lo: alloe set so t;at durin# fa>ri9ation or s;op= site

;ined stresses in an< s;ell 9omponent

Pa#e 6 of 1$%


9/129

IndianOil



E>ased on 9orrosion t;i9?ness for site testF doe not eB9eed t;efollo:in#EaF )ensile %!G am>ient F Compressive Code allo:a>le stress

1." T!PE OF PRESSURE VESSELS

i. Ce

supported in different :ae9omes ne9essare9ause of t;e statutor< reAuirements.

1.& T!PES OF INSPECTION

);ere are t:o t


10/129

IndianOil



e de9ided. );e period >et:een inspe9tions s;ould >eplanned so t;at some 9orrosion allo:an9e remains :;en t;e vessel ista?en out of servi9e for inspe9tion. Normall< in t;e refineries, it is notpossi>le to isolate a vessel or a 9olumn for internal inspe9tion :;en t;eunit is on-stream. 5en9e t;e internal inspe9tion of t;e pressure vesselis pro#rammed alon# :it; t;e unit over;aul. 5o:ever, t;e freAuen9< of

eBternal inspe9tion 9an >e de9ided deepenin# on ;istore stri9tlile pressure vessels EunfiredF Rule1%61, all vessels s;all >e ;


11/129


IndianOil


Pa#e 11 of 1$%


12/129


IndianOil


.0 SUPPLEMENTAR! SPECIFICATION FOR CLADDEDPRESSURE VESSELS

.1 SCOPE

);is supplementar< spe9ifi9ation 9overs t;e additional reAuirements to>e follo:ed in t;e manufa9ture of 9ladded steel vessels, :it; 9ar>onsteel or lo: allo< steel >ase, 9lad :it; stainless steel. );is is intendedas an addenda to t;e #eneral spe9ifi9ation for pressure vessel=supplementar< spe9ifi9ation for C. vessels.

. DESIGN

);e desi#n t;i9?ness, in a99ordan9e :it; t;e spe9ified 9ore, s;all notin9lude an< material used for applied 9orrosion resistant linin# or t;e

9laddin# material on inte#rall< 9lad plate.

);e use of 9laddin# material of 9;romium allo< stainless steel :it; a9;romium 9ontent more t;an 1G is not re9ommended for servi9emetal temperature a>ove $!C.

trip linin# is not allo:ed unless spe9ified on en#ineerin# data s;eet.

2llo< linin# for s;ells and ;eads s;all >e inte#rall< >onded 9laddin# or:eld deposit overlae used atdesi#n temp. a>ove $"!!C.

2usteniti9 stainless steel no@@les are not permitted unless ot;er:isespe9ified on t;e vessel data s;eet.

No@@les and man:ae made :it; :eld deposit, :;i9; is atleast as t;i9? as t;e vessel linin# :;en properl< ma9;ined and of t;esame allo< as t;e linin#. 4eld deposit s;all >e made :it; minimum t:opasses.

Lar#e no@@les and man:ae made >e used. );ee :elded to t;e allo< fa9in# at t;e surfa9e of t;e vessel ma< >e>< :eldin#, flus; :it; t;e vessel inside surfa9e, or an eBpansion 9ollar.

." MATERIAL

Clad steel plates used for fa>ri9ation of vessel s;all 9onform to 2 $"or 2 $ of 2M' 3 & pressure vessel 9ode se9tion II part 2, and

C5) spe9ifi9ation no. C5)-!-II-Part-.

Pa#e 1$ of 1$%


13/129


IndianOil


In t;e allo< lined portions of t;e vessel, all internal parts li?e supportrin#s, lu# supports and ot;er s;all >e made of allo< 9orrespondin# tot;e linin# or as spe9ified in en#ineerin# data s;eets.

.% FA-RICATION

Clad plates s;ould >e ;andled in t;e s;op :it; 9lad side up, to avoiddama#e to 9lad surfa9e.

2deAuate pre9autions s;ould >e ta?en durin# s;earin# andpur9;asin#, ma9;inin#, flame 9uttin# and ;ot :or?in# of 9lad plates soas to avoid an< dama#e to t;e 9lad surfa9e.

5ot :or?in# s;ould >e follo:ed >< suita>le ;eat treatment to ensurereAuired material properties.

.& *ELDING

);e use of filler metal, t;at :ill deposit :eld metal :it; t;e same or>etter 9omposition as t;e material oined, is re9ommended.

4eldin#, in 9onun9tion :it; allo< linin#, is re9ommended to >e done:it; ele9trodes or filler :ires made in a99ordan9e :it; t;e spe9ifi9ationlisted >elo:

Sl.No.

Applie7 li4i4g Coa3e7 elec3o7es=o SMA* Pocess

Fille GTA*$Pocess

*ie GMA* =oSA*

Allo> 3os3eel

Allo> 3oallo>

Allo> 3o s3eel Allo> 3o allo>

1. 2$! t


14/129


IndianOil


2llo< to steel :eld ' "!% Mo2llo< to allo< :eld ' "!% Mo

(or "0 9lad vessels, 9olum>ium 9ontent of :eld metal s;all noteB9eed 1.!G eB9ept :;en a ;i#;er 9olum>ium 9ontent is permitted in

t;e material >ein# :elded.

4;en inte#rall< >onded 9lad plate is used, t;e linin# s;all >e 9ut >a9?at all seams to permit >a9? :eldin# of t;e >ase metal. 4eld metal s;all>e #round flus; and full< 9overed :it; t;e appli9a>le :eld depositoverla< in para#rap; .$ of t;is spe9ifi9ation. );e :eld deposit overlae at least as t;i9? as t;e linin# >ut not #reater t;an t:i9e itst;i9?ness.

);e :eld oint in t;e >a9?in# C plate s;all >e 1!!G defore 9lad side :eldin# is

applied.

Load >earin# internal parts, supported from s;ell= ;ead EeB9ept trae :elded to t;e >ase metal.

);e :eld deposit overla< pro9edure s;all >e Aualified on >ase metal oft;e same 9omposition as t;e vessel and t;i9?ness of one-;alf of t;evessel t;i9?ness, or $ in9;es, :;i9;ever is less.

);e :eld overla< pro9edure s;all >e Aualified on >ase metal of t;esame 9omposition as t;e vessel and t;i9?ness of one ;alf of t;e vesselt;i9?ness, or $ in9;es, :;i9;ever is less.

);e :eld overla< s;all >e applied 9ir9umferentiall< to t;e vessel ands;all >e relativel< smoot; :it; no not9;es and under 9uts t;at :oulda9t as stress intensifiers. (la:s on t;e surfa9e of t;e >ase metal t;at:ould interfere :it; >oundin# of t;e overla< s;all >e removed >e repaired >< :eld deposit overla< ina99ordan9e :it; para#rap; .$ of t;is spe9ifi9ation. 4;en repairs ineB9ess of per9ent of t;e total eBamined area are reAuire, t;e vessels;all >e 1!!G ultrasoni9 eBamined. Repaired areas and :eld depositoverla< at :eld seams s;all >e 1!!G liAuid dF 4;en t;e overla< involves t:o or more passes Elae 1!!G re-inspe9ted >< liAuid de ultrasoni9all< eBaminedafter final ;eat treatment or vessel, for la9? of >ond. Inspe9tion andrepair pro9edure s;all >e as per .$ a>ove.

.+ #EAT TREATMENT

aF Cladded vessels or parts of vessels s;all >e post :eld ;eat treated:;en t;e >ase material is reAuired to >e P.4. ;eat treated as per9ode.

>F Vessels ;avin# strai#;t 9;romium stainless steel 9laddin#= linin#s;all >e P.4. ;eat treated in all t;i9? nesses, eB9ept vessels 9lad:it; te P.4. ;eat treated unless reAuired >< 0.1EaFa>ove.

4;en 9ar>on steel vessels, 9lad= lined :it; unsta>ili@ed austeniti9

stainless steel ot;er t;an lo: 9ar>on #rade e.#. "! and "1,are to >e post :eld ;eat treated, t;e< s;all >e ;eat treated at 1! !C

Pa#e 1 of 1$%


16/129


IndianOil


for a period of 1! ;ours per in9; of t;i9?ness or 1! ;ours :;i9;ever islon#er.

(ollo:in# pre9autions s;ould >e o>served durin# ;eat treatment of9lad vessels.

iF );e 9lad material s;ould not >e eBposed to a dire9t flame if #as oroil is used as a fuel.

iiF tainless steel 9lad steels reAuire a neutral or oBidi@in# atmosp;eredurin# ;eatin#.

iiiF MaBimum sulp;ur 9ontent in t;e fuel s;ould not eB9eed !.G.ivF Mar?in# paint and prote9tive oil s;ould >e removed from t;e 9lad

side >efore ;eatin#.vF );e plates s;ould ;e >e ;eated :it; 9lad side up.

., SURFACE CLEANING

tainless steel 9lad surfa9e must >e 9leaned from oBides, s9ale,:eldin# fluB et9. >< usin# :ire >rus;es. Paint s;all >e removed >le solvent Efree from 9;loridesF. Oil and #rease s;all >eremoved usin# ;ot 9lean :ater and suita>le deter#ent.

2fter 9ompletion of fa>ri9ation and testin#, all stainless steel 9ladsurfa9e s;all >e pi9?led and passivated, in a99ordan9e :it; 2)M a"6!. Pi9?lin# and passivation pro9edure s;all >e su>mitted for revie:.

);e stainless steel surfa9es s;all >e free of iron pi9? up. );is s;all >edete9ted >< ferroB


17/129


IndianOil


Pa#e 10 of 1$%


18/129


IndianOil


".0 PRESSURE VESSELS IN T#E SERVICE OF #!DROGEN$#!DROGEN SULFIDE$ SOUR SERVICES ETC.

".1 RE)UIREMENTS FOR #!DROGEN SERVICES

a 5listers to form.

>F Resistan9e to ;tained >< t;e additionof 9;romium and= or moldenum in t;e metal sin9e t;ese elementsform more sta>le 9ar>ides t;an iron. );e limits of resistan9e of9ar>on steel and various alloasis of materials sele9tion for vessels in t;is servi9e.Refer atta9;ed NelsonHs 9;art for referen9e.

9F 4;ere additional 9orrosion due to ;e reAuired and for t;is purpose.3a9?enstoHs 9urves 9o-relatin# 9orrosion rates :it; ;< a ;ase plate.2llo< linin# used for t;is purpose s;all >e >onded inte#rall< :it; t;e>ase plate :it; t;e final >ond lae used in ;e9ause of t;ermal eBpansion pro>lems and t;e possi>ilit< of;uildin# up >e;ind t;e linin#.

". RE)UIREMENTS FOR SULFUR CORROSION

aF ulfur >earin# streams are onl< mildl< 9orrosive to 9ar>on steel attemperatures >elo: $!! C. 2t ;i#;er temperatures, 9;romiumsteels ma< >e reAuired to 9om>at sulfur 9orrosion. (or 9orrosive9onditions, eit;er solid G Cr steel or 1$G Cr 9lad steel s;ould >eused, dependin# upon e9onomi9s and availa>ilitF Materials sele9tion and 9orrosion allo:an9es s;ould prefera>l< >e2PI >ased on a9tual servi9e eBperien9e.

Pa#e 16 of 1$%


19/129


IndianOil


"." RE)UIREMENTS IN SOUR SERVICE

);e dis9over< and o99urren9e of surfa9e 9ra9?in# eit;er resultin# fromt;e fri9ation or from sulfide stress 9orrosion 9ra9?in# ECCF,>listerin# and su>-surfa9e 5e9omin# Auite 9ommon in pressure vessels t;at operateunder sourH 9onditions. (urt;ermore, it is no: 9onsidered to >eunrealisti9 to distin#uis; >et:een 4et 5$ ervi9eH and eneralervi9esH. Durin# startup and s;utdo:n of eAuipment, moisture :illoften >e present in refiner< streams, :;i9; eB9eed !ppm 5$.5o:ever, unless liAuid :ater is present durin# operatin# 9onditions ordama#e to eAuipment ;as alread< >een eBperien9ed, desi#nin# forsour servi9e ma< not >e :arranted.

2lt;ou#; most pro>lems ;ave >een eBperien9ed in (CC+ over;eads,9rude and va9uum over ;eads, amine treatin# and sour :ater strippin#

se post ;eat treated irrespe9tive of stora#eappli9ation and adopted s;ell t;i9?ness.

>F N2C' tandard

In t;e past, it ;as >een a99epted pra9ti9e to use N2C' tandard Mr1-066 to determine t;e material suita>ilit< for refiner< sourservi9e even t;ou#; t;is standard :as prepared spe9ifi9all< for Oil(ield 'AuipmentK.

Pa#e 1% of 1$%


20/129


IndianOil


N2C' re9ommended Pra9ti9e RP-!0$ 60 #ives #uidan9e on t;e;ardness limits of 9ar>on steel :elds to resist 9orrosive petroleumrefinin# environments.

9F Inspe9tion

2ll :elds on t;e pressure envelopes must >e #round smoot;

and >lended into t;e ;eat-affe9ted @one prior to testin#.

)estin# onl< >< t;e :et fluores9ent ma#neti9 parti9le

Pro9edure in a99ordan9e :it; 2M' e9tion V s;all >e used.

)estin# s;all >e 9arried out after post:eld ;eat treatment is

9omplete.

)estin# s;all >e 9arried on t;e follo:in# :elds

- );e inside and outside of all vessel :elds in9ludin# no@@les.- upport stru9ture :elds :;ere t;e< atta9; to t;e pressure

envelop.- Vessel >ra9?et and 9lip :eldsH in9ludin# an< temporarF (or appli9ations a>ove "1 de#. C and :;en 9orrosion rates for! to G 9;rome steels eB9eed .!" ipe 9onsidered as t;e< are #enerall< more e9onomi9al t;an1$G Cr. Material.

9F E9F 4;en austeniti9 stainless steels=austeniti9 9lad steels arereAuired to resist ;elo:"%6 de#. C te used.

dF EdF (or appli9ations a>ove "%6 de#. C, teused :;en an austeniti9 material is reAuired for 9orrosionresistan9e. );e materials s;ould >e sta>ili@ed >< ;eatin# at 601 J6%6 de# C for $ ;ours rat;er t;an solution annealed. 2lso9onsideration s;ould >e #iven to t;e need for a post:eld ;eattreatment to sta>ili@e t;e :eld metal and ;eat affe9ted @one and to

relieve residual stresses.

Pa#e $! of 1$%


21/129


IndianOil


".& SPECIFIC CONDITIONS *#ERE POST*ELD #EAT TREATMENTIS RE)UIRED

'Auipment 9onstru9ted of 9ar>on steel must >e post:eld ;eat treated

:;en ;andlin# t;e follo:in# material

1. odium and potassium ;


22/129


IndianOil


Pa#e $$ of 1$%


23/129


IndianOil


%.0 DESIGN P#ILOSOP#! OF TALL COLUMNS

Tall Col254s

Me9;ani9al desi#n of self-supportin# tall 9olumn=to:er s;all >e 9arried

out #enerall< >ased pro9edure outlined in Pro9ess 'Auipment Desi#nK>< Llo


24/129


IndianOil


:ind on 9olumn s;all >e 9onsidered for analF Opea3io4 - Column Ein 9orroded 9onditionF under desi#npressure, in9ludin# :elded items, trale on 9olumn,

insulation and operatin# liAuid et9. plus full :ind or insulated 9olumn:it; all ot;er proe9tions open to :ind or eart;Aua?e for9es s;all >eused for anal


25/129


IndianOil


iiF 3 value 9al9ulated as per +-$" E>F of Code.

>F Allo6aBle 3e4sile s3ess ?MaBimum allo:a>le tensile stresses atoperation and am>ient temperatures for operatin# and ere9tionloadin# 9onditions s;all >e desi#n 9ode allo:a>le stress as per +

$" EaF multiplied >< oint effi9ien9le stress s;all >e ta?en as %!G of e limited to 9odeallo:a>le stress & for s?irt material multiplied >< !.% or !.0 dependin#upon :;et;er t;e :eld in s;ear or tension. 5o:ever, allo:a>le9ompressive stresses in :eld are 9al9ulated as per C1..1 >ased onstren#t; of s?irt material.

S:i3 S2ppo3 -ase

3ase supportin# in9ludin# >ase plate, an9;or 9;airs, 9ompression rin#,foundation >oltin# et9, s;all >e desi#ned >ased on usin# over turnin#moment E#reater of seismi9 or :indF. 2 minimum num>er of 6foundation >olts s;all >e provided. Nos. of foundation >olts s;all >emultiple of four.

Ma7o3es3 Pess2e

MaBimum 5e eAual to1. B Desi#n pressure B temperature 9orre9tion fa9tor, as spe9ified in2M' 9ode se9tion VIII Div.1. Clause +-%%.

D>4a5ic A4al>sis o= Col254To6e

Dilit< undertransverse :ind indu9ed vi>rations as per standard desi#n pra9ti9e.);e re9ommended ma#nifi9ation fa9tor for unlined to:ers=9olumn s;all

>e ta?en as 0! and allo:a>le de limited toto:er diameter divided >< five.

Pa#e $ of 1$%


26/129


IndianOil


A44ee 9onsidered allaround.

Pa#e $ of 1$%


27/129


IndianOil


Pa#e $0 of 1$%


28/129


IndianOil


&.0 C#EC' LIST FOR INSPECTION OF PRESSUREVESSELS PRIOR TO ERECTION AND COMMISSIONING

);e 9;e9?list format s;all 9ontain t;e follo:in# information.

'Auipment No.

Plant

Dutserved. 5o:ever, t;e follo:in# lo9ations

#ive indi9ation of deterioration= 9ra9?in#.

i. Cra9?in# of :eldment of #rid :it; s;ell at t;e >ottom.ii. 3as?ets for 9olle9tin# t;e 9atali# diameter no@@les are sus9epti>le to

>ul#in# due to failure of :eld oints at t;e end.iv.Rea9tors made of lo: allo< steel spe9iall< $-Cr J 1Mo are prone to

temper em>rittlement. E)emper em>rittlement is defined as a loss ofdu9tilit< and not9; tou#;ness due to post :eld ;eat treatment or;i#; temperature servi9e a>ove "0!!CF.

&.1.( Reac3os i4 FCCU

);e s;ell, riser O.D. and portion of t;e 9


31/129


IndianOil


);e failure of refra9tor< linin# on t;e s;ell is anot;er 9ommon pro>lem.Durin# operation, it ma< 9ause ;ot spots on t;e s;ell. 'rosion of9


32/129


IndianOil


&.1.1 A55o4ia S3oage Vesselsenerall< t;e stora#e vessels are fa>ri9ated from Car>on teel andNi9?el teels. (or t;e operatin# 9onditions prevailin# at refineries,material of 9onstru9tion used for ammonia stora#e vessels in t;erefineries are 9ar>on steels. );e :eld oints of C.. vessels are prone

to stress 9orrosion 9ra9?in# parti9ularl< in t;e vessels :;i9; ;ave not>een stress relieved initiall< or after fa>ri9ation= repairs.

&.1.1" Col254s Vessels i4 Die38>l A5i4e Mo4oe38>l A5i4e Se;ice

);e :eld oints and ;eat affe9ted @one of t;e 9olumns and vessels inD'2 and M'2 servi9e :;i9; ;ave not >een stress relieved are alsoprone to 9ra9?in# due to presen9e of 5$ or 5$ and 5$.

&. FRE)UENC! OF INSPECTION

i. 2ll ne: vessels, re#ardless of servi9e s;all >e inspe9ted :it;in first$ e s9;eduled on t;e >asis of esta>lis;ed 9orrosion rates, t;etased on ;istoret:een inspe9tions s;all >e planned so t;at minimum9orrosion allo:an9e remains for t;e neBt run. In an< 9aseinspe9tion freAuen9ies as per statutor< reAuirements s;all >e stri9tlatter< area s;ould >e done durin# s9;eduled turnarounds, unlessinspe9tion o>servations and 9orrosion rates di9tate ot;er:ise.Ot;er pressure vessels installed in offsite s;all >e internalle 9;e9?ed durin# t;e eBternal

inspe9tion

i. (oundation & upports

EaF (oundations

(oundations for pressure vessels are mostl< 9onstru9ted of steelreinfor9ed 9on9rete or of fire proofed stru9tural steel. );ese s;all>e 9;e9?ed for spallin# 9ra9?in# and settlement. If due to 9ra9?s,>i# #aps ;ave >een formed, steel s;ould >e 9;e9?ed for eBternal9orrosion >< removin# t;e 9on9rete at 9ra9?ed lo9ations.

E>F ?irts

?irts s;all >e inspe9ted for 9orrosion, distortion and 9ra9?in#,from outside as :ell as from inside. );e :eat;er proofin# on t;eeBtremeties and fire proofin# of stru9tural supports s;all >e9;e9?ed for :ater ti#;tness.

);e inside of t;e s?irt is often su>e9ted to 9orrosion. );is isparti9ularl< true for vessels operatin# under 9re done toassess t;e eBtent of deterioration. );e 9ondition of fire proofin#on support >eams and s?irts s;all >e inspe9ted for >ul#in# and9ra9?s. Ver< li#;t taps :it; a ;ammer :ill indi9ate la9? of >ond>et:een fire proofin# and steel. 2ppearan9e of rust stains on t;esurfa9e of fire proofin# is an indi9ation of moisture in#ress andpresen9e of 9orrosion on t;e metal underneat;. If t;ere isreason to suspe9t t;at :ater or moisture ;as seeped t;rou#; tot;e steel, po9?ets of insulation s;ould >e removed to determinet;e eBtent of 9orrosion. 5o:ever, inspe9tion of t;e s?irt afterremoval of fireproofin#= insulation s;all >e done at an interval not

#reater t;an e 9;e9?ed for9ra9?in#.

E9F upport of 5ori@ontal Vessels

5ori@ontal vessels restin# on 9on9rete saddle supports :;ere:ater 9an a99umulate and 9ause eBternal 9orrosion s;all also>e inspe9ted. 5ori@ontal vessels operatin# at ;i#; temperaturess;all >e 9;e9?ed to ensure free t;ermal eBpansion.

ii. (oundation= 2n9;or 3olts

Pa#e "" of 1$%


34/129


IndianOil


(oundation >olts s;all >e inspe9ted for 9orrosion and dama#e. );enuts on an9;or >olts ma< >e inspe9ted to see t;at t;ese areproperl< ti#;tened.

iii. Ladders, tair:ae inspe9ted visuall< for 9orrosion, 9ra9?s, paint failureet9. Visual inspe9tion s;all >e supplemented >< ;ammer testin#.Corrosion is most li?el< to o99ur at points :;ere moisture 9ana99umulate. Crevi9e 9orrosion ma< eBist around t;e ;eads andnuts of >olts. Ladders s;all >e eBamined for free movement to ta?eup eBpansion of t;e vessels.

iv. Insulation and Prote9tive Coatin#s

Visual eBamination of insulation :ill reveal its 9ondition. Insulation

s;ieldin# s;all also >e 9;e9?ed for Aualit< and t;i9?ness. 2t fe:lo9ations samples ma< >e removed to determine 9ondition of t;einsulation and of t;e metal underneat;. Plant or prote9tive 9oatin#s;all eBamined for peelin# or rustin#. Insulation s;ieldin# s;ould >einta9t. If at an< time insulation s;ieldin#= 9laddin# is >lo:n off ordama#ed t;e same s;all >e put >a9? immediatel< after repairs toavoid 9orrosion. );e insulation retainin# rin#s s;all >e 9;e9?ed tosee t;at moisture is not trapped >et:een t;e rin#s and t;e:eldment. );e pressure vessels operatin# at ;i#; temperature areinsulated from outside and t;e s?irt is insulated #radient >et:eens?irt and s;ell :eld oint. 2n< dama#e to t;is insulation is li?el< to9ause t;e 9ra9?in# of t;is oint. 5en9e t;e insulation s;all >einspe9ted to ensure t;at t;e same is inta9t.

v. round Conne9tions

roundin# 9onne9tions s;all >e visuall< eBamined to see t;at #oodele9tri9al 9onta9t is maintained. );e 9a>le s;all >e eBamined for>ro?en strands. Its resistan9e s;all >e 9;e9?ed at intervals asoutlined in OID standard-1"0 EInspe9tion of 'le9tri9al 'AuipmentF.

vi. No@@les and small Conne9tions

);e no@@les on a pressure vessel s;all >e visuall< inspe9ted andt;i9?ness surveon steelno@@les ma< >e ;ammer tested. mall diameter no@@les Eless t;an!mmF are diffi9ult to >e t;i9?ness surve< ta?in# radio#rap;s :;ereverpossi>le. );e tell-tale ;ole in t;e reinfor9ement pad s;all >e9;e9?ed for possi>le lea?s.

pe9ial attention s;ould >e #iven to nipples used for pressure and

temperature #au#es et9. );ese nipples s;all >e 9;e9?ed t;orou#;le 9;e9?ed

Pa#e " of 1$%


35/129


IndianOil


for an< lea?a#e. 2n< lea?a#e :ill indi9ate dama#e of t;e linin#. Iflea?a#e is o>served, pressure testin# t;rou#; tell-tale ;ole and testnipples s;all >e done durin# internal inspe9tion to lo9ate t;e lea?s.Care s;all >e ta?en to ?eep t;e plu#s on t;e tell-tale ;oles loose.

vii. 'Bternal Inspe9tion of Metal urfa9e

EaF Visual Inspe9tion

);e eBternal surfa9e of t;e pressure vessel s;all >e inspe9tedvisuallrittlement, ;listerin#, t;ermal fati#ue and me9;ani9al dama#e. If 9austi9 isstored or used in a vessel it s;all >e 9;e9?ed for 9austi9em>rittlement. );e areas around t;e no@@les and in or ada9entto :eld seams are sus9epti>le to t;is te determined >< visual inspe9tion. 5listerin# is more often found on t;e inside rat;er t;an outside>< ma< >e found at eit;er pla9e dependin# upon t;e lo9ation oft;e void, :;i9; 9auses t;e 9ondition. 3listers are found mosteasil< >< visual eBamination. );e s;ell s;ould >e 9;e9?ed for>u9?les and >ul#es. );ese 9an >e found and measured >F 4eld oints

);e :eld oints and ;eat-affe9ted @ones E527F s;all >e 9;e9?edvisuall< for 9ra9?s. In 9ase of dou>t it s;ould >e 9;e9?ed >< de

9;e9?ed durin# operation. );e areas :;i9; ;ave development;ot spots durin# servi9e s;all also >e 9;e9?ed for me9;ani9aldama#e su9; as #ou#es and dents, lea?s, 9ra9?s and oBidationof an< eBternal stiffeners.

EdF +ltrasoni9 Inspe9tion

);i9?ness measurement of t;e s;ell and domes ma< >e ta?enfrom outside. 'Ba9t lo9ation of t;i9?ness measurement ma< >ede9ided after internal inspe9tion onl


36/129


IndianOil


Pressure vessel :;i9; operates on t;ermal 9er and at ;i#; temperature li?e orifi9e 9;am>er in (CC+s;all >e t;orou#;l< inspe9ted from outside. In 9ase of 9o?e9;am>er if t;e entr< of feed is at t;e >ottom, insulation of atleast $ to " 9ourses all around s;all >e removed. );e s?irt to

s;ell :eld oints s;all >e t;orou#;l< 9;e9?ed for 9ra9?s. );e>ottom flan#e :eldin# :it; t;e s;ell s;all also >e inspe9ted. );e:eld oints, 527 and s;ells of $ to " 9ourses s;all >e 9;e9?edfor 9ra9?s and apparent >ul#in# et9. Presen9e of suspe9ted9ra9?s s;ould >e 9onfirmed >< usin# De 9;e9?ed for 9ra9?in#.

EfF LP Vessels

LP >ullets and sp;eres ;avin# fireproofin# on t;e outsidesurfa9e s;all >e eBamined for 9ra9?s, spallin#, >ul#in# and

deterioration of fireproofin#. 2ppearan9e of rust stains on t;esurfa9e of fireproofin# is an indi9ation of presen9e of 9orrosion ofmetal underneat;. If a>out indi9ations are apparent t;efireproofin# in suspe9ted areas s;all >e removed and t;eeBternal surfa9e s;all >e inspe9tion for an< 9orrosion.

I43e4al I4spec3io4

Pressure vessels entr< s;all >e made onl< :it; an appli9a>le :or?permit as detailed in OID-)D-1! on :or? permit se inspe9ted internall< s;all >e de9ided >ased on t;epast ;istor< of t;e eAuipment. 2vaila>le past ;istor< s;all supplementt;e standard inspe9tion pro9edure of t;e eAuipment. );e inspe9tion ofa 9olumn is divided into t;e top, feed and >ottom @ones. If installedeAuipment is >ein# inspe9ted for t;e first time, t;an all tra< man:ae opened and t;e 9omplete inspe9tion s;all >e 9arried out.Internal inspe9tion 9an >e divided into t:o parts.

i. Preliminar< Inspe9tion

Prior to s9;eduled s;utdo:n of t;e unit t;e pressure vessel s;all >e

eBamined from t;e outside to dete9t an< unusual 9ondition durin#operation, su9; as lea?s in no@@le :elds t;rou#; tell-tale ;oles or#as?ets, t;e 9ondition of t;e >olts and flan#es, t;e apparent9ondition of insulation and an< ot;er visi>le defe9ts. Durin#s;utdo:n, >efore 9leanin# t;e 9olumn from inside, preliminare done. O>servations re#ardin# internaldislod#in# et9. s;all >e noted. amples of deposits s;all >e9olle9ted for anale #iven.

Pa#e " of 1$%


37/129


IndianOil


ii. Detailed Inspe9tion

EaF )op 7one

)op dome, s;ell and internals in t;e top @one s;all >e visualle done to lo9ate 9orrosion, erosion,;listerin#, 9ra9?in#, laminations or me9;ani9aldama#e. pe9ial attention s;all >e #iven to :eld oints andsurfa9e 9onditions. If pits are noti9ed, dept; of pits s;ould >emeasured :it; dept; #au#e or pit #au#e. ;ell plates >elo: t;erefluB no@@le s;all >e inspe9ted for an< possi>le #roovin#.RefluB 9olle9tor s;all >e 9;e9?ed for t;innin#. pouts and9ounter spouts s;all >e 9;e9?ed >< ;ammer testin# for findin#an< possi>le deterioration. );e trae9;e9?ed for pittin# and 9ra9?in#. );i9?ness of dome and s;ellnear t;e s;ell and dome :eldin# s;all >e ta?en in all four

dire9tions E', 4, N and F. );i9?ness of t;e dome around t;eno@@les s;all >e ta?en. ample t;i9?ness of 9olumn internalsli?e do:n9omer, do:n9omer 9olle9tors and support platess;ould >e ta?en. 3esides t;is, if at 9ertain lo9ations of s;ell ormeasured at t;ese lo9ations to ?no: t;e eBa9t loss. ;ell at t;edo:n9omer 9olle9tor level s;all >e 9;e9?ed for an< possi>leliAuid level 9orrosion in t;e form of #roovin#. Referen9e pointss;ould >e mar?ed on s;ell, dome and no@@les and same s;ould>e monitored for t;i9?ness durin# ever< inspe9tion to determinerate of metal :asta#e.

E>F (eed 7one

4;ile inspe9tin# t;e feed @one Eflas; @oneF, t;e impin#ementplate s;all >e 9;e9?ed for an< 9orrosion= erosion and properatta9;ment :it; s;ell. ;ell plates s;all >e inspe9ted near t;eimpin#ement plate :;ere t;ere is a possi>ilit< of fluidimpin#ement. );e internals s;all also >e inspe9ted. );i9?ness oft;e s;ell plates in four dire9tions and t;e impin#ement plate s;all>e ta?en. ample t;i9?ness s;ould also >e ta?en on internals.

E9F 3ottom 7one

In t;e >ottom @one, >ottom dome and s;ell s;all >e inspe9ted.pe9ial 9are is to >e ta?en at t;e area near t;e >ottom dra: off.If pittin#s are o>served, pit dept; s;ould >e measured. 2t steamine9tion points t;e s;ell plate opposite to steam no@@le s;all >et;orou#;l< inspe9ted for possi>le impin#ement. 2ll t;e internalpipin#s et9. s;all >e inspe9ted. );i9?ness and ;ammer testin#:;erever possi>le s;ould >e 9arried out. 2ll t;e no@@lesin9ludin# t;e man;ole no@@les and retra9ta>le spool pie9e s;all>e t;i9?ness survee >ro?en to fa9ilitate t;i9?ness survele to approa9; t;e no@@le, ID

Pa#e "0 of 1$%


38/129


IndianOil


measurements from inside s;all >e ta?en to determinet;i9?ness.

EdF Columns in 5le ;listerin#. 5listers s;all >einspe9ted and evaluated as outlined in 2nneBure-III.

In 9atalars forinternal eAuipment su9; as 9e 9losel< eBaminedfor t;is tle to erosion and s;all >e9losel< eBamined for t;is te 9;e9?ed for 9ra9?in# and dama#e.Out of roundness or >ul#in# ma< >e evaluated >< measurin# t;e

inside diameter of t;e vessel at t;e 9ross se9tion of maBimumdeformation and 9omparin# it :it; t;e ori#inal inside diameter. Ift;e >ul#in# is at intervals, t;e measurement 9an >e done > line and ta?in# t;e measurements at sele9tedintervals. );is :ill also reveal t;e 9ontour of t;e s;ell.

Inspe9tion of Lined Columns

2usteniti9 stainless steel 9olumns and 9olumns lined :it; austeniti9 plates s;all >e passivation as per t;e pro9edure #iven in N2C' RP-!1-0! >efore openin# t;em in order to prote9t t;em a#ainst stress9orrosion 9ra9?in#.

i. triplined Column

Pro9edure for inspe9tion of striplined 9olumn is similar to t;eunlined 9olumn as eBplained a>ove :it; 9ertain 9riti9al lo9ations asoutlined >elo: needin# spe9ial attention. trips s;all >e visualle #iven to t;e :eld oints and527 of :elds, :;ere 9ra9?in# 9an ta?e pla9e. If 9ra9?s aresuspe9ted, de 9arried out. );e strips s;all

also >e inspe9ted for >ul#in#. );e strip linin# s;ould >e 9;e9?ed >e around!.$-?#= sA. 9m >ut in no 9ase s;ould it eB9eed !$.?#= sA. 9m. );earea :;ere t;e strip linin# ends s;all >e 9;e9?ed 9arefull< as9orrosion ma< ta?en pla9e due to #alvani9 a9tion of strip linin# and9ar>on steel s;ell. );i9?ness on t;e C portion s;all >e measured.No@@le liner s;ould >e tested >< pressuri@in# t;e area >et:een t;eliner and no@@le >< air t;rou#; test nipple. );e pressure s;all noteB9eed !.?#= sA. 9m. 2fter testin#, t;e test nipple s;all >e ?eptopen and 9apped onl< :;en t;e plant= eAuipment is 9ommissioned.Ot;er:ise >ul#in# of t;e liner ma< ta?e pla9e. );i9?ness of t;e

strips s;all >e measured at pla9es to as9ertain :;et;er strips ;ave

Pa#e "6 of 1$%


39/129


IndianOil


>een su>e9ted to an< 9orrosion. );i9?ness surve< of t;e 9olumns;all >e done from outside to 9;e9? t;e parent material t;i9?ness.

ii. Cladded Columns

Claddin# s;all >e visuall< 9;e9?ed for an< deterioration li?e9orrosion= erosion, pittin#, >ul#in# et9. );i9?ness at desi#natedlo9ations s;all >e measured to 9;e9? t;e >ondin# of t;e 9laddin#metal :it; parent metal. );e portion :;ere t;e 9laddin# ends, s;all>e 9;e9?ed for 9orrosion :;i9; ma< ta?e pla9e due to #alvani9a9tion. );e :eld oints and 527 s;all >e 9;e9?ed for 9ra9?s. No@@leliners s;ould >e 9;e9?ed in a similar :a< as eBplained in para EiFa>ove.

iii. Inspe9tion of Internall< Painted 2rea

);e temperature limitations of t;e paintin# se ?no:n. 4;ile s;uttin# do:n a unit, :ater flus;in#s;all >e resorted to instead of steam flus;in#. If steam flus;in# isne9essare ta?en t;at flus;in# steam temperatures;ould not #o >e< t;e paintmanufa9turer. );e painted surfa9e s;all >e 9leaned >< :ater:as;in# and t;en moppin# :it; 9otton or ute. Cleanin# :it; :ire>rus; s;all not >e resorted to. Man entr< s;all >e >< :earin# softs;oes or >are foot. Paintin# s;all >e visuall< inspe9ted andt;i9?ness s;ould >e measured :it; paint t;i9?ness #au#e and t;esame s;all >e 9ompared :it; ori#inal D() of paintin# se 9;e9?ed for ;olida


40/129


IndianOil


In t;e strippin# se9tion, stripper s;ell and steam no@@le s;all >einspe9ted for erosion. );i9?ness measurements of stripper s;ells;all >e done. Condition of t;e linin# in t;e fiBed and remova>lese9tions in feed riser pipe s;all >e 9;e9?ed. Inverted V-tello:sat t;e eBpansion oint s;all >e inspe9ted for perforations. Inspe9tion

of steam and 9atale9arried out.

In t;e plenum 9;am>er, s;ell s;all >e inspe9ted for erosion andt;i9?ness measurements s;all >e ta?en. afet< valve inlet no@@lesand vapour outlet line s;all >e inspe9ted for t;innin# and plu##in#.

In t;e anti9o?in# 9;am>er, perip;erial ;oles s;all >e 9;e9?ed forplu##in#. Ce ;ammer tested. ;ell and:eld oints >et:een s;ell and >ottom plate s;all >e inspe9ted.);i9?ness measurements of t;e s;ell s;ould >e made.

);e internal linin# of riser pipe s;all >e inspe9ted :it; t;e ;elp of a9a#e lo:ered from t;e rea9tor. );e >ud >ae removedand t;e 9ondition of *-se9tion s;all >e 9riti9all< eBamined forerosion and 9ra9?in#. 4;enever, dissimilar :eld oints eBist in t;eriser pipe, t;ese s;ould >e 9;e9?ed for 9ra9?s. );e rea9tion andre#eneration standpipes s;all >e eBamined for failure of internallinin# and metal deterioration. );e 9onvolutions of eBpansion>ello:s s;all >e 9;e9?ed for deposits. );e slide valves s;all >eeBamined for erosion and proper operation.

ii. Re#enerator

);e s;ell linin# s;all >e 9;e9?ed for deterioration. Parti9ularattention s;ould >e #iven ust near man:a< and in areas >e;ind t;e#rid seal. 2eration 9onne9tions, t;ermo-:ells and tri9?le valvess;all >e inspe9ted.

Linin# for primar< 9e 9;e9?ed. pe9ial 9are s;ould>e ta?en in t;e areas at inlet ;orn, >arrel, ;eliB and 9ones. Diple#ss;all >e inspe9ted for perforations. 5an#ers and supports, sprae inspe9ted.Linin# of t;e plenum 9;am>er and sta9? a>ove t;e plenum9;am>er s;all >e inspe9ted. 'mer#en9< steam spraeinspe9ted for oBidation. If t;e plenum 9;am>er is of material, t;e>imetal :eld oint >et:een 9;am>er and s;ell s;all >e eBaminedfrom inside.

rid plates s;all >e 9;e9?ed for >ul#es and t;i9?ness. rid seals;all >e inspe9ted for 9ra9?s or perforations. Overflo: :ell and seal>oBes s;all >e 9;e9?ed for erosion and perforations. Linin# of t;e

9one >elo: #rid s;all >e inspe9ted. 2uBiliar< >urner tips, air doorand t;e pilot s;all >e inspe9ted visuallurner

Pa#e ! of 1$%


41/129


IndianOil


dome and t;e linin# of t;e dome on t;e inside s;all >e 9arried out.Lu#s and supports for t;e auBiliar< >urner dome s;all also >einspe9ted.

iii. Orifi9e C;am>er

);e orifi9e 9;am>er s;ell s;all >e inspe9ted for erosion. );e areasust after t;e Dou>le Dis9 lide Valve EDDVF s;all >e inspe9ted9riti9alleeBamined for in9reased diameter due to erosion. );e s;ell ada9entto #rid plate s;ould >e eBamined for an< deformation, 9ra9?s ordeterioration after removin# t;e insulation at random from outside.);e dis9s of DDV s;all >e eBamined for erosion and properoperation.

&.". I4spec3io4 o= Vessel

E


42/129


IndianOil


i. Con9rete, unite & Refra9tor< Linin#s

Con9rete, #unite and refra9tor< linin#s inside a pressure vessels;all >e visuall< 9;e9?ed for me9;ani9al dama#e su9; as spallin#and 9ra9?s. Parti9ular attention s;ould >e #iven at lo9ations :;ere

;ot spots ;ave >een noti9ed durin# operation. Minor 9ra9?s andareas of porosit< are more diffi9ult to find. Li#;t s9rappin# :illsometimes reveal su9; 9onditions. 3ul#in# :;i9; 9an >e lo9atedvisuall< is usuall< a99ompanied >< 9ra9?in# in most 9ases. If9orrosion o99urs >e;ind a 9on9rete linin#, t;e linin# :ill lose its>ond :it; steel. );e sound and feel of li#;t ;ammer tappin# :illusuall< ma?e su9; looseness evident. If 9orrosion >e;ind a linin# issuspe9ted small se9tion of t;e linin#s s;all >e removed for s;ellinspe9tion. );is :ill also permit a 9ross se9tional eBamination of t;elinin#. In 9ases :;ere >are metal ;as >een eBposed >e9ause oflinin# failure, visual inspe9tion s;all >e made of t;e eBposed metal.

);i9?ness of t;e s;ell s;all >e measured from outside.

ii. Ru>>er Lined Pressure Vessel

ome pressure vessels are ru>>er lined from inside for prote9tiona#ainst 9orrosion. );e ru>>er linin# s;all >e inspe9ted forme9;ani9al dama#e, ;oles, 9ra9?in#, >listerin#, >ondin# et9. 5olesin t;e linin# are eviden9ed >< >ul#in#. 2 ;olida< dete9tor s;ould >eused to t;orou#;l< 9;e9? t;e linin# for lea?s and ;olidae ta?en so t;at t;e test volta#e does not approa9; a valuet;at mi#;t pun9ture t;e linin#. tandards are availa>le for values oftest volta#es as per t;i9?ness of ru>>er linin#. (or inspe9tin#ru>>er-lined vessels, I-6$-Part-I s;all >e referred. 3ondin# oft;e ru>>er linin# s;ould >e 9;e9?ed ultrasoni9all< from t;e outside.

Riveted Vessels

3esides t;e internal and eBternal inspe9tion as #iven earlier, rivetedvessels s;all >e eBamined for ti#;tness of rivets, soundness of9aul?in# and seal :elds and ot;er 9onditions. (or t;e insulated rivetedvessel, insulation s;ould >e removed from all oints for 9;e9?in# at 16

mont;s intervals.

Corrosion Coupons= Pro>es

Corrosion 9oupons are installed in t;e pressure vessels to evaluatea99uratel< t;e 9orrosion rate or to evaluate a ne: material in t;eeBistin# environment. 4;ile doin# t;e internal inspe9tion t;e 9orrosion9oupons if installed s;ould >e ta?en out. Nature of 9orrosion atta9? ont;e 9orrosion 9oupons s;all >e studied. );e 9oupons are t;ent;orou#;l< 9leaned and :ei#;t loss in a spe9ified len#t; of time s;all>e 9al9ulated. );is #ives t;e 9orrosion rate and 9leaned 9oupons are

a#ain installed for future evaluation. Corrosion pro>es ma< >e installedat vulnera>le lo9ations on t;e pressure vessels for onstream

Pa#e $ of 1$%


43/129


IndianOil


monitorin# of 9orrosion rates. Coupons and pro>es 9an >e eit;er fiBedor retra9ta>le te revisioned and tested. (or details on inspe9tion of pressurerelievin# devi9es OID-td-1"$ s;all >e referred.

Retirin# t;i9?ness

3efore determinin# t;e limitin# or retirin# t;i9?ness of an< pressurevessel, it s;ould >e determined under :;i9; 9ode it ;as >eenmanufa9tured. Retirin# t;i9?ness s;all >e 9al9ulated as per appli9a>le9ode as most vessels are >uilt :it; some eB9ess t;i9?ness in vessel:alls and ;eads, over t;at reAuired to :it;stand t;e internal operatin#

pressure. );e eB9ess t;i9?ness ma< result from an< one or more of t;efollo:in# fa9tors

i. 'B9ess t;i9?ness as a result of usin# a nominal t;i9?ness of platerat;er t;an t;e eBa9t EsmallerF value 9al9ulated.

ii. 'B9ess t;i9?ness availa>le as a result of settin# minimum t;i9?nessof t;e plates for 9onstru9tion purposes.

iii. 'B9ess t;i9?ness availa>le as a result of 9;an#e in vessel servi9e,>< redu9in# safet< valve settin# or maBimum metal temperature or>ot;.

Retirin# t;i9?ness for man< a99essories of pressure vessels are not9overed in t;e 2M' 9ode neit;er are t;e met;ods of 9al9ulatin# su9;t;i9?ness. ome of t;ese parts are traaffles, ladders and platforms. (or some of t;e eAuipment, t;ereare #enerall< a99epted met;ods of settin# retirin# t;i9?ness. Minimumt;i9?ness s;ould >e developed for all su9; eAuipment. );e results ofpossi>le failure of su9; eAuipment s;ould >e 9onsidered for settin#t;ese limits. afet< and 9ontinuous effi9ient operation are t;e prime

fa9tors affe9tin# retirin# t;i9?ness for t;ese 9omponents. Repair orrepla9ement s;ould >e 9arried out :;en t;e< ;ave lost one ;alf t;eirori#inal t;i9?ness. );e retirin# t;i9?ness for no@@les and internalpipin#s s;all >e 9al9ulated >< appli9a>le 9odes or 2NI standards.4idel< s9attered pits ma< >e i#nored provided

EaF No pit dept; is more t;an one ;alf t;e vessel :all t;i9?nesseB9lusive of t;e 9orrosion allo:an9e.

E>F );e total area of t;e pits does not eB9eed sAuare 9entimeters:it;in an< $! 9entimeter diameter 9ir9le, and

Pa#e " of 1$%


44/129


IndianOil


E9F );e sum of t;eir dimensions alon# an< strai#;t line :it;in t;e 9ir9ledoes not eB9eed 9entimeters.

2s an alternative to t;e pro9edures des9ri>ed a>ove, an< t;innin# of9omponents >elo: minimum reAuired :all t;i9?ness due to 9orrosion

or ot;er :asta#e ma< >e evaluated to determine t;e adeAua9< for9ontinued servi9e >< emplo< anal


45/129


IndianOil


ome portion of s;ell plates and domes of pressure vessels ma< #ett;inned due to 9orrosion or erosion. );e t;i9?ness of t;e affe9ted areama< rea9; t;e retirin# t;i9?ness. In su9; 9ases, partial repla9ement ofs;ell plate or dome is 9arried out as :eld repair of t;e >i# area is notpra9ti9all< possi>le. );e affe9ted portion is 9ut and removed. );e ne:

plates mat9;in# :it; t;e metallur#< and t;i9?ness of t;e ori#inal plateis made availa>le.

);e ed#e preparation s;all >e done as per t;e 9ode reAuirement >e 9;e9?ed for 9ra9?s, fla:s anddefe9ts >< ma#nif< usin# de performed eit;er frominside our outside. );e root run s;all >e t;orou#;l< inspe9ted for9ra9?s and fla:s. 2fter 9ompletin# t;e :eldin# from one side, t;e ot;erside is 9;ipped and #round. 3efore :eldin# a#ain, t;e #roove is

9;e9?ed for 9ra9?s and defe9ts. 4eldin# is t;en 9ompleted from t;eot;er side. Complete :eldin# s;all >e visuall< 9;e9?ed andradio#rap;ed as per t;e appli9a>le 9ode. Detailed inspe9tion of:eldin# s;all >e done as outlined in 2nneBure-II.

Pre;eat and post :eld ;eat treatment s;all >e 9arried out as per t;ereAuirement of relevant 9ode. In order to 9;e9? :;et;er post :eldtreatment ;as >een 9arried out properle ta?en after P45). );e ;ardness readin#ss;ould >e minimum as indentation mar?s reAuired durin# ;ardnessmeasurement a9t as stress riser and t;is leads to stress 9on9entration.If post :eld eat treatment is reAuired it is re9ommended to 9arrefore post :eld ;eat treatment also. );e defe9ts in t;e:eldin# are repaired >< #ou#in# and re:eldin#. In lie of radio#rap;e 9arried out.

#>7os3a3ic Tes3

2fter satisfa9tor< inspe9tion and radio#rap;le 9ode. );epressure s;ould >e ;eld for a minimum of "! minutes. Durin# ;e installed at t;e ;i#;est point. It isre9ommended t;at t:o pressure #au#es >e used. );e ran#e of t;epressure #au#e s;ould >e "!G more t;an test pressure and 9ali>ratedpressure #au#es s;all >e used. );e area, :;i9; ;as >een repaired,s;ould >e t;orou#;l< 9;e9?ed for lea?s and si#ns of deformation. );epressure drop s;all also >e noted. 3efore su>e9tin# t;e 9olumn=vessels to ;e 9;e9?ed for :ater load. 2usteniti9 pressure vessels s;all >e pressure tested usin# DM :ater orpassivatin# solution. 5e done as per t;e relevant 9ode.

P4e25a3ic Tes3i4g

Pa#e of 1$%


46/129


IndianOil


4;en testin# pneumati9alle used as an aidto visual inspe9tion. );is soap solution is >rus;ed over t;e seams andoints on t;e vessel. );e vessel is t;en eBamined for eviden9e for>u>>les as an indi9ation of lea?s. Often a vessel, :;i9; operates at ava9uum, ma< >e pressure tested. );is is t;e prefera>le testin# met;od,

:;en feasi>le, >e9ause it permits t;e lo9ation of an< lea?s. 4;enpressure testin# is not feasi>le, a va9uum vessel 9an >e tested forlea?s >< 9reatin# a va9uum >< means of eva9uators or va9uum pumpsinstalled in t;e units. If t;e va9uum 9an >e ;eld for a spe9ified timeafter 9losin# off t;e eva9uators or va9uum pumps, it is an indi9ationt;at t;e vessel is free of lea?s.

If t;e va9uum 9annot >e ;eld, lea?s are present >ut t;is met;od #ivesno indi9ation of t;eir lo9ation. 2 sear9;, :;i9; ma< >e diffi9ult, mustt;en >e made to tra9e t;e lea?s. It is su##ested t;at pneumati9 testin#s;ould >e avoided as far possi>le and if at all is to >e 9arried out it

s;ould >e done in a99ordan9e :it; relevant 9ode.

Repai o= Cla77i4g a47 S3ipli4i4g

);e >ul#ed, 9ra9?ed or ;eavil< pitted 9laddin# inside t;e pressurevessels s;all >e repaired. );e deteriorated 9laddin# in removed >< :eldin#,usin# proper ele9trodes as per 9laddin# and s;ell metallur#e 9;e9?ed visuall< and >< usin# D.P. for defe9tsand 9ra9?s et9. t;e :eldin# s;ould >e done is a sta##ered manner toavoid distortion of t;e s;ell. 4;en t;e dama#ed area is >i#, aftersealin# t;e remainin# 9laddin#, striplinin# of t;e area 9an >e done.EDetails of striplinin# and :eldin# pro9edure is #iven in 2nneBure J II.F3ul#ed striplinin# is repla9ed >< pun9turin# t;e linin# to removeentrapped air. );e >ul#ed portion of t;e linin# is flattened >< li#;t;ammerin# and t;en :elded. If t;e striplinin# ;as 9ra9?ed or ;eavile removed and fres; linin# put. );e:eld oints are 9;e9?ed for fla:s and 9ra9?s >< DP and visualeBamination. 4;ile removin# or pun9turin# t;e 9laddin#= striplinin#,

ne9essar< pre9autions s;ould >e ta?en as ;on ma< >eentrapped in >et:een t;e linin# and s;ell.

Repai o= Pai43e7 a47 R2BBe li4e7 Aeas

If t;e paintin# in a small area of a vessel ;as peeled off or ;as >eendama#ed, pat9;-paintin# repair 9an >e done. );e dama#ed areas s;all>e painted :it; ori#inal paintin# slasted to :edis;standard a $-1=-$ to 9lean t;e surfa9e and ori#inal paintin# s>er linin# of vessels ;as >ul#ed or 9ra9?ed in asmall area, t;e deteriorated linin# s;all >e removed and fres; ru>>er

Pa#e of 1$%


47/129


IndianOil


linin# is put in t;at small area. Ne: linin# s;all >e 9;e9?ed for ;oles andfla:s. Lo9al 9urin# s;ould >e done to a9;ieve ;ardness of !2Es;ore ;ardness J 2F. 4;en a lar#e area of t;e ru>>er linin# ;as9ra9?ed and >ul#ed, t;e dama#ed linin# is ta?en out. 3are metal is9leaned >< s;ot >lastin#. Ne: ru>>er linin# is provided. Curin# s;all >e

done to a9;ieve Q !2 Es;ore ;ardness 2F. );e linin# s;all >evisuall< 9;e9?ed for 9ra9?s, ;olida< and >ul#in#. );e ;olidae9;e9?ed >< usin# ;olida< dete9tor. (or inspe9tin# t;e ru>>er linin# I-6$-Part I s;all >e referred.

Doc25e43a3io4

O>servations of ea9; inspe9tion s;all >e properl< re9orded. 2fterdeterminin# t;e 9orrosion rate and remainin# 9orrosion allo:an9e,repair and repla9ement of a pressure vessel 9an >e planned. );efollo:in# 9ards s;all >e used for proper do9umentation of t;e inspe9tion

findin#s

i. Data 9ard ERef. (orm No 1Fii. IndeB 9ard ERef. (orm No $Fiii. 5istor< 9ard ERef. (orm No "Fiv. Data Re9ord 9ard ERef. (orm No Fv. Development ?et9; ERef. (i#ure & F

&.& REPAIRS$ ALTERATION AND RE?RATING OF PRESSUREVESSELS

Oga4ia3io4

A238oia3io4

Need of repair, alteration and re-ratin# of pressure vessels ma< 9omeas a result of

i. Inspe9tion findin# a>out 9orrosion, 9ra9?in# and ot;er te used as #uidelines for de9idin# a>out aut;ori@ed person tore9ommend ne9essar< repair= alteration and= or re-ratin#.

O64e?2se I4spec3io4 Oga4ia3io4

O:nerHs Inspe9tion 'n#ineers s;all >e aut;ori@ed person. 5o:ever,;ead of inspe9tion s;all aut;ori@e su9; inspe9tion en#ineers :it;

suita>le Aualifi9ation and eBperien9e in :ritin# and t;en onl< t;e< :ill>e aut;ori@ed to re9ommend repairs.

Pa#e 0 of 1$%


48/129


IndianOil


In 9ase of alterations and re-ratin#, t;e re9ommendations s;all >e#iven in 9onsultation :it; Desi#n and Pro9ess 'n#ineers.

A238oie7 I4spec3io4 Age4c>

2n aut;ori@ed inspe9tion a#en9< 9an >e

);e inspe9tion or#ani@ation of t;e urisdi9tion in :;i9; t;e pressurevessel is used.

'Bplanation

i.Pressure vessels desi#ned and used as per I3R s;all needaut;ori@ation of 3oiler Inspe9tor= C;ief 3oiler Inspe9tor.

ii. Pressure vessels fallin# under MPV rule :ill need aut;ori@ation

from CC', Na#pur or its re#ional offi9es :;i9; 9an >e o>tained if,t;e repair pro9edure is approved >< t;e CC' approved t;ird partri9ators for pressure vesselsfallin# under MPV EunfiredF Rule J 1%61.

iv. 2n or#ani@ation ;older of a valid 2M' 9ertifi9ate of aut;ori@ationfor t;e use of an appropriate 2M' 9ode sol stamp.

Sa=e3> oga4ia3io4

2s t;ese pra9ti9es are mainl< appli9a>le to pressure vessels at

installations of Petroleum Companies ;andlin# inflamma>le,

Pa#e 6 of 1$%


49/129


IndianOil


;a@ardous, toBi9 produ9ts, also laid do:n safet< pre9autions of o:ner-user or#ani@ation & OID is to >e stri9tl< follo:ed >< all 9on9erned.

Repai a47 Al3ea3io4 o= Pess2e Vessels

eneral J all proposed met;ods of repairs, materials :eldin#9onsuma>les & :eldin# pro9edure to >e used and testin# of :elders isto >e approved >< aut;ori@ed inspe9tion prior to 9ommen9ement ofrepair :or?.

De=ec3 epai cac:s

Repair of 9ra9?s found in :eld oints and parent plate material s;all >emade after preparation of proper + or V #roove dependin# upon t;edept; and len#t; of 9ra9?s. 3efore fillin# t;e #rooves :it; :eld deposit,it s;ould >e ensured t;at 9ra9?s ;ave >een full< removed >< suita>le

ND) pro9edure.

Repai o= pi3s

2fter removal of surfa9e irre#ularities and 9ontamination li?e oil, #reaseet9., it 9an >e repaired :it; :eld deposit. Isolated pits ;avin# dept;less t;an ;alf t;e :all t;i9?ness eB9lusive of 9orrosion allo:an9e mae 9onsidered>efore finali@in# t;at repair is needed or not

i. );e total pit area does not eB9eed 9m$ in a 9ir9le of $! 9m.ii. On an< strai#;t line :it;in t;e 9ir9le t;e sum of dimension of pits

does not eB9eed 9ms.

Repai o= coo7e7 aea

Corroded areas s;ould >e restored :it; :eld metal deposit aftersurfa9e preparation li?e removal of irre#ularities >< #rindin# andremoval of 9ontaminations >< suita>le means. Dependin# uponprevious o>servation Ein 9ase of pressure vessels :;i9; are in lon#useF 9orrosion rate s;ould >e de9ided and a repair of 9orroded area

9an >e deferred to neBt planned M&I opportunit< if remainin# 9orrosionallo:an9e is eBpe9ted to >e more t;an ;alf of total 9orrosion allo:an9eori#inall< provided.

In 9ase of ne: vessels, if on first inspe9tion pressure part of t;e vesselis found 9orroded to a 9onsidera>le eBtent, t;e reasons of 9orrosionma< >e investi#ated >< eBperien9ed personnel and if reAuired properprote9tive strip linin# of ;i#;er metallur#< s;ould >e 9onsidered.

ENote for ;out approB. !!C strip linin# ma< not #ive satisfa9tor< prote9tionF.

Pa#e % of 1$%


50/129


IndianOil


Dependin# upon t;e total 9orroded area repaired >< :eld deposit mae9ome une9onomi9al and time 9onsumin#. 5en9e, in 9ase of lar#e9orroded area repla9ement s;ould >e 9onsidered. );e repla9ementplate ma< >e of t;e same t;i9?ness or ;i#;er t;i9?ness 9ompared toori#inal t;i9?ness. Repla9ement plate s;all >e >end to reAuired radius

and s;all ;ave prefera>l< rounded 9orners.

If pressure vessel is ver< old and ne: repla9ement plate is not of same#rade as ori#inal, or t;ere are reasons to >elieve t;at old plate mi#;t;ave #one metallur#i9al 9;an#e, it is ne9essar< to 9arr< out :elda>ilitefore 9arronper9enta#e more t;an !.$G s;all not >e used for repla9ement of9orroded area.

Repai 6el7i4g poce72e

Repair :eldin# pro9edures are not different from :;at is used forfa>ri9ation of ne: vessels.

5o:ever, sometimes some innovative te9;niAues of :eldin# repair li?e)emper 3ead 4eldin#K or "! !C >ondin# on lo9al repairsK ma< #ivesome relief to repair or#ani@ation. 5o:ever, adoption of t;esete9;niAues reAuires 9onsultation :it; eBperien9ed en#ineer in t;e fieldof pressure vessel desi#n, :eldin# et9. );ese te9;niAues s;all not >eused :;ere P45) is due to servi9e reAuirement.

);ese approa9;es of repairs alon# :it; ne9essar< pre9autions aredes9ri>ed >elo:

EaF )emper 3ead 4eldin#

2 temper >ead :eldin# te9;niAue ma< also >e used in lieu ofpost:eld ;eat treatment for P-1 and P-" materials >< t;e follo:in#pro9edures

i. );e :eld area s;all >e pre;eated and maintained at aminimum temperature of 10 !C durin# :eldin#. );e maBimum

interpass temperature s;all >e $"!!

C.

ii. );e initial lae deposited over t;eentire area :it; 1=6K E" millimeterF maBimum diameterele9trodes. 2pproBimatel< one-;alf t;e t;i9?ness of t;is lae removed >< #rindin# >efore depositin# su>seAuentlaseAuent lae deposited :it; ="$K E-millimeterF maBimum diameter ele9trodes in a manner toensure temperin# of t;e prior >eads and t;eir ;eat affe9ted@ones. );e final >ead reinfor9ement lae removedsu>stantiall< flus; :it; t;e surfa9e of t;e >ase material or t;e

previous :eld la


51/129


IndianOil


iii. 5eat input s;all >e 9ontrolled :it;in a spe9ified ran#e of:eldin# 9urrent and volta#e.

iv. );e :eld area s;all >e maintained at a temperature of $! !CE=-F $6 !C for a minimum period of $ ;ours after 9ompletion of

t;e :eld repair.

v. );e performan9e of t;e repair :eldin# s;all >e 9arried out inpresen9e of Inspe9tor.

vi. );e :eld metal s;all >e deposited >< t;e manual s;ieldedmetal are pro9ess usin# lo: ;ead :idt; s;all >e four times t;e ele9trode 9orediameter.

vii. If a :elded pat9; is applied to a riveted vessel, t;e :elded

oint must ;ave at least t;e effi9ien9< of t;e riveted lon#itudinaloint. 2 :elded pat9; applied too 9lose Esaout 19entimetersF to a riveted oint ma< result in oint lea?a#e.Riveted oints ma< >e sealed >< me9;ani9al 9aul?in# or seal:eldin# in a99ordan9e :it; t;e 2M' 9ode after 9arefullF Lo9al Post:eld 5eat )reatment

Lo9al post:eld ;eat treatment EP45)F ma< >e su>stituted for "!!C >andin# on lo9al repairs on all materials provided t;e follo:in#pre9autions and reAuirements are applied.

i. );e appli9ation is revie:ed and a pro9edure is developed >ilit< of a pro9edure, 9onsideration s;all>e #iven to appli9a>le fa9tors, su9; as >ase metal t;i9?ness,de9a< t;ermal #radients, and material properties E;ardness,9onstituents, stren#t;, and so fort;F, 9;an#es due to P45),

t;e need for full penetration :eld, and surfa9e and volumetri9eBaminations after P45). 2dditionalle9onsidered in evaluatin# and developin# P45) pro9edures.

iii. 2 pre;eat of 1! !C or ;i#;er as spe9ified >< spe9ifi9 :eldin#pro9edures, is maintained :;ile :eldin#.

iv. );e reAuired P45) temperature s;all >e maintained for adistan9e of not less t;an t:o times t;e >ase metal t;i9?ness

measured from t;e :eld. );e P45) temperature s;all >emonitored >< a suita>le num>er of t;ermo9ouples Eminimum of

Pa#e 1 of 1$%


52/129


IndianOil


t:oF 9onsiderin# t;e si@e and s;ape of t;e area >ein# ;eat-treated.

v. 5eat s;all also >e applied to an< no@@le or ot;er atta9;ment:it;in t;e P45) area.

vi. );is pro9edure :ill not >e used for LP, 2mmonia and ot;ersu9; servi9es :;ose P45) is done irrespe9tive of t;et;i9?ness as a servi9e reAuirement.

E9F Desi#n 2spe9ts of Repair

3utt oints s;all ;ave 9omplete penetration and fusion. Parts s;ould>e repla9ed :;en repair is li?el< to >e inadeAuate.

Ne: 9onne9tions ma< >e installed on vessels provided t;e desi#n,

lo9ation, and met;od of atta9;ment are a99ordin# to t;e prin9iplesof t;e appli9a>le 9ode.

(illet :elded pat9;es reAuire spe9ial desi#n 9onsiderations,espe9iall< relatin# to effi9ien9e applied to t;einternal or eBternal surfa9es of s;ells, ;eads, and ;eaders providedt;at, in t;e ud#ment of t;e inspe9tor, t;e proposed pat9; eit;er

i. Provides eAuivalent safet< to a reinfor9ed openin# desi#neda99ordin# to t;e appli9a>le 2M' 9ode se9tion, or

ii. I desi#ned to a>sor> t;e mem>rane strain of t;e part in amanner su9; t;at in a99ordan9e :it; t;e rules of t;e appli9a>le2M' 9ode se9tion

);e allo:a>le mem>rane stress is not eB9eeded in t;e

vessel part or t;e pat9;.

);e strain in t;e pat9; does not result in fillet :eld stresses,

:;i9; eB9eed allo:a>le stresses for su9; :elds. 2n insert oroverla< pat9; s;all ;ave rounded 9orners.

I4spec3io4

299eptan9e 9riteria for a :eld repair or alteration s;ould in9lude non-destru9tive eBamination te9;niAues in a99ordan9e :it; t;e appli9a>le9ode or vessel ratin# 9ode. 4;ere t;is is not possi>le or pra9ti9al,alternative non-destru9tive eBamination met;ods ma< >e used.

Tes3i4g

2fter repairs are 9ompleted a pressure test s;all >e applied if deemedne9essar< in t;e opinion of t;e inspe9tor. Pressure tests are normallri9ation pro9edures and non-destru9tive eBamination mae 9onsidered in lieu of a pressure test, su>stitutin# spe9ial pro9edures

Pa#e $ of 1$%


53/129


IndianOil


for a pressure test after an alteration ma< >e done onl< after9onsultation :it; an en#ineer eBperien9ed in pressure vessel desi#n.2n< de9ision on t;is ma< reAuire permission from aut;orit< of statutorle.

Re?Ra3i4g

Re-ratin# a pressure vessel >< 9;an#in# t;e temperature ratin#s or t;emaBimum allo:a>le :or?in# pressure ma< >e done onl< after all of t;efollo:in# reAuirements ;ave >een met

i. Cal9ulations from eit;er t;e manufa9turer or an o:ner-useren#ineer eBperien9ed in pressure vessel desi#n, fa>ri9ation, orinspe9tion, or ;is desi#nated representative s;all ustif< re-ratin#.

ii. 2ll re-ratin#s s;all >e esta>lis;ed in a99ordan9e :it; t;e

reAuirements of t;e 9ode to :;i9; t;e pressure vessel :as >uiltor >< 9omputation usin# t;e appropriate formulas in a later editionof t;e 2M' 9ode, if all essential details 9ompl< :it; t;eprin9iples of t;e 9ode >ein# used.

iii. Current inspe9tion re9ords verif< t;at t;e pressure vessel issatisfa9tor< for t;e proposed servi9e 9onditions and t;at t;e9orrosion allo:an9e provided is appropriate.

iv. );e pressure vessel ;as at some time >een pressure tested ina99ordan9e :it; t;e ne: servi9e 9onditions, or t;e vessel inte#rit< spe9ial non-destru9tive evaluation inspe9tionte9;niAues in lieu of testin#.

v. );e pressure vessel re-ratin# is a99epta>le to t;e inspe9tor.

);e pressure vessel re-ratin# :ill >e 9onsidered 9omplete :;en t;einspe9tor oversees t;e atta9;ment of an additional nameplate oradditional stampin# 9arr


54/129


IndianOil


Pa#e of 1$%


55/129


IndianOil


(.0 )UALIT! ASSURANCE PLAN FOR NE*CONSTRUCTIONS

/ualit< assuran9e plan of ne: fa9ilities needs attention ri#;t from t;edesi#n sta#e, P&ID revie:, 9;e9?s durin# detail en#ineerin#,9onstru9tion Aualit< 9ontrol. ele9tion of t;e 9ommissionin# team andt;e leader is also vital to ensure Aualit< of t;e final fa9ilite loo?ed into durin# t;ese sta#es are su##ested as under.

(.1 )UALIT! ASSURANCE DURING DESIGN STAGE

);e finali@ation of desi#n >asis ;as to >e done :it; meti9ulous 9are.);e spe9ifi9ation and (ront 'nd 'n#ineerin# Desi#n E(''DF,pro9urement, 9onstru9tion and 9ommissionin# sta#es need adeAuateinvolvement of proe9t team.

);e P(D and P&ID revie:s and laerevie:ed 9riti9all< t;e detailed en#ineerin# 9ontra9tor also needst;orou#; revie:.

/ualit< 2ssuran9e Plan E/2PF s;ould >e developed in advan9e toensure relia>ilit< of t;e ne: fa9ilit


56/129


IndianOil


ome spe9ifi9 points ;ave >een listed >elo: >ased on t;e re9enteBperien9es of 9ommissionin# of ne: fa9ilities. );ese aspe9ts s;ouldalso >e ta?en 9are of durin# t;e desi#n sta#e to ensure relia>ilit< of t;ene: fa9ilities.

iF 2ll small >ore pipin#s and tra9er lines, si@e K and >elo: s;ould>e :elded >< )I pro9ess for all tutt, so9?et,tee, et9. to ensure proper Aualit< of :eldin#. +se of ;alf 9ouplin#ma< >e 9onsidered to in9rease relia>ilit< of small->ore9onne9tions.

iiF Minimum t;i9?ness of pipe for si@es upto 1SK s;ould >e 9;. 6!for C and 2.

iiiF Reinfor9ement pad s;all >e provided at support lo9ation.

ivF team drain points s;ould >e routed to a drain ;eader and ta?enout of t;e unit area.

vF 2s far as possi>le lon# trunion te avoided. In 9ase of lon# trunion supports areunavoida>le in strai#;t len#t; of pipe, it is to >e provided :it;reinfor9ement pad on t;e pipe.

viF tiffener s;ould >e provided in small->ore >leeder= drain point9onne9tion :elded to immediate upstream or do:nstream ofsafet< valves.

viiF (ire fi#;tin# points are to >e provided at ;i#;er elevation in 9aseof tall 9olumns, stru9tures.

viiiF 2s far as possi>le, stu> in tran9; 9onne9tion are to >eprovided :;en >ran9; si@e is less t;an one si@e t;an t;e mainpipe.

iBF 2ll t;e reinfor9ement pad telltale ;oles s;ould >e drilled andtapped properle a99epted.

BF );e supports :elded on insert plates in t;e RCC 9olumns s;ould>e 9;e9?ed for t;eir adeAua9< to >ear t;e reAuired loads andmovements of t;e se fiBed :it;an9;or fasteners #routed in RCC 9olumn.

BiF Insulation :indo:s for inspe9tion and t;i9?ness surve< are to >eprovided in insulatin# vessels at all approa9;a>le lo9ation :it;provision of 9aps to avoid in#ress of :ater.

BiiF 4;erever insulation is to >e provided on vessel for ;uman safete repla9ed >< a 9a#e of 1K I :ire mes; :rapped

Pa#e of 1$%


57/129


IndianOil


around t;e pipin# :it; t;e ;elp of spa9ers ta9? :elded on t;e:ire mes;.

BiiiF 2ll t;e fittin#s li?e valves, flan#es et9. in ;i#; temperature servi9eET U "!! !CF s;ould also >e full< insulated if t;e< are in open area

or t;e lo9ali@ed 9oolin# 9an 9ause operational pro>lems li?e9o?in# et9.

BivF 2ll 9onne9tions s;ould ;ave 9;loride free insulation orprefera>l< s;ould ;ave foil :rapped >et:een pipe andinsulation.

BvF No 9ast iron valves s;ould >e used in fire:ater or an< ot;erservi9e.

(. )UALIT! ASSURANCE DURING CONSTRUCTION STAGE

In spite of >est efforts in t;e desi#n sta#e, t;e Aualit< of ne: fa9ilities9anHt >e assured :it;out proper involvement of Inspe9tion & Proe9tteam of t;e O:ner. );e sele9tion of t;e Proe9t team and9ommissionin# team is t;e most vital aspe9t for t;e su99essful9ommissionin# of t;e ne: fa9ilit< and unfortunatel< is t;e mostne#le9ted in our 9ase.

);e O:ner supervision durin# 9onstru9tion 9anHt >e diluted inspite of;avin# PMC, 'PC or L)8 9ontra9tors.

);e );ird Part< Inspe9tion 2#en9ies, :;erever emploedifferent from t;e eBe9utin# a#en9e spelt out;o:ever, to mention fe: one must ta?e 9are of t;e follo:in#s

iF prin# te unlo9?ed and 9old set prior to9ommissionin# of t;e s< t;e 9ontra9tor as per t;einstru9tions of sprin# support manufa9turer in presen9e of PMC=O:nerHs representative.

2 9omplete list of all t;e sprin# supports in a parti9ular units is to>e 9ompiled alon#:it; relevant do9uments & details andsu>mitted to IOCL Inspe9tion & Maintenan9e Department prior toMe9;ani9al 9ompletion of t;e Proe9t.

Movement of t;e sprin# supports to >e 9losel< o>served durin#startup and re9orded till s


58/129


IndianOil


iiiF 2ll t;e matin# flan#es 9onne9tin# to eAuipment li?e J Columns,Vessels, 5eat 'B9;an#ers, Pumps, Compressors et9. are to >e:elded after proper ali#nment and levelin# of terminal eAuipmentto avoid t;e misali#nment and tension at no@@le flan#es.

ivF Pipin# 9onne9tions passin# t;rou#; te9;nolo#< stru9ture ERCCfloorsF or passin# near t;e 9on9rete 9olumn et9. s;ould ;aveadeAuate annular spa9e to avoid restri9tion of line movementdurin# t;ermal eBpansion. );e #ap s;ould >e ta?en 9are for ;otlines alon#:it; insulation t;i9?ness.

vF 2ll t;e R) rin# #as?ets s;ould ;ave proper identifi9ation mar?in#:it; metallur#i9al 9ertifi9ate availa>le.

viF Positive Material Identifi9ation EPMF s;ould >e 9arried out for allt;e 9omponents of 2llo< teel, tainless teel and ot;er ;i#;er

metallur#< pipin# and 9;e9?ed on t;ree-tier >asis to ensure9orre9t metallur#ri9ation & ere9tion at site. );e properle #iven a distin9t 9olour >< supplier>efore dispat9; to avoid an< miBin# :it; ot;er material. );irdPart< Inspe9tor s;ould also 9ertif< PMI.

Part of t;e :eld oints s;ould also >e 9arried out for 2llo< teel=tainless teel 9ir9uits in-situ. );is s;ould >e in9orporated in t;e9ontra9t.

viiF 'le9tri9al resistan9e 9oils s;ould >e used for pre ;eatin#= post;eatin# of all t;e allo< steel :eldin# of dia. $K and a>ove. Pre;eatin#= post ;eatin# s;ould >e made mandator< for all t;e alloutt :eld si@es.

viiiF )emperature re9orders used in stress relivin# s;ould >e9ali>rated and t;e related 9ertifi9ate s;ould >e availa>le at site forverifi9ation.

iBF Contra9tor, :;o is a:arded t;e :or? involvin# use of lo:

;le for >a?in# ofele9trodes at "!! !C.

BF 4eldin# of allo< steel >utt :eld oints s;ould not >e leftin9omplete for lon# ;ours. 'arlier in fe: 9ases, onl< root run :asdone on a da< and remainin# :eldin# :as planned neBt dae spe9ifi9all< 9ertified >< 'n#ineer-in-9;ar#e= Inspe9tor.

BiiF 2ll 9riti9al servi9e #ate= #lo>e= 9;e9? valves s;ould >e site testedprior to installation.

Pa#e 6 of 1$%


59/129


IndianOil


BiiiF 2ll t;e supports of a pipin# se 9;e9?ed for t;eir9orre9tness and adeAua9< after 9omplete installation >< t;eDesi#ner to avoid an< pro>lem durin# operation.

BivF (lus;in# s;ould >e done properl< after droppin# t;e safet< valvesand 9ontrol valves et9. to avoid an< in#ress of forei#n material.Proper flus;in# to t;e satisfa9tion of Produ9tion Departments;ould >e part of main 9ontra9t.

BvF 2ll pipin# se drained and air flus;ed after;ello:s installed area :ise alon#:it;spares supplied s;ould >e ;anded over to IOCL Inspe9tion &Maintenan9e Department >< 9onsultant= 9ontra9tor.

BviiF 3ello:s s;ould >e 9;e9?ed for proper supportin#.

BviiiF 3ello:s s;all >e unlo9?ed prior to 9ommissionin# in presen9e ofPMC= O:nerHs representatives.

Distin9t 9olour 9ode to >e used for different materials Ein9ludin# I3RmaterialsF for pipin# and fittin#. On t;e pipes, t;e 9olour strips s;all9over t;e full len#t; of pipe and >ends. );is 9olour mar?in# s;all >epart of pur9;ase order for 9omplian9e at t;e supplierHs end.

(." )UALIT! ASSURANCE PLAN FOR VESSELS

S.No.

Ac3i;i3> co5po4e43I4spec3io4Descip3io4

Re=ee4ceDoc25e43

1. Revie: of :eldin# pro9edure,spe9ifi9ation & pro9edureAualit< re9ord

4eldin# parameters,:eldin# 9onsuma>le& an< ot;er supplementarlo9? su9; as a Ri9?i ) is used to 9al9ulate t;e

remainin# :all t;i9?ness of t;e pipe. );e eBposure sour9e is usuallalt ! used for t;e pipes of ;eavier :all t;i9?ness.Profile radio#rap;< is an effe9tive evaluation met;od, >ut >e9omeste9;ni9all< 9;allen#in# in pipin# sod< 9an :or?:it;in t;e area :;ile t;e inspe9tion is under :aut limited to

a small area. It is eBpensive to 9ut t;e insulation ;oles and 9over t;e;oles :it; 9aps or 9overs. It is not pra9ti9al to 9ut enou#; ;oles to #eta relia>le result. );e inspe9tion ;oles 9ut in t;e insulation malem, if t;e< are not re9overed 9arefulle used todete9t damp spots in t;e insulation, >e9ause t;ere is usuall< adete9ta>le temperature differen9e >et:een t;e dr< insulation and t;e:et insulation. Corrosion is a distin9t possi>ilit< in t;e areas >eneat;t;e :et insulation.

Neutron Backscatter:);is s


66/129


IndianOil


In;i>itors su9; as Na$iO" ;ave >een tried :it; vareen s;o:n t;at sometimes

t;ese te9;niAues tend to lo9? in moisture, :;i9; 9an also in9rease9orrosivitest >utmost eBpensive options to prevent 9orrosion under insulation is t;euse of prote9tive 9oatin# sut not in ot;ers. +se of @in9 ri9; paint, ;o:ever, is not permitted onstainless steel >e9ause of its sus9epti>ilit< to em>rittlement in9onta9t :it; liAuid @in9. 2s a matter of fa9t even #alvani@ed :ire or:ire nets Efor retainin# insulation in positionF are not to >e used. In9ase of fire t;e molten @in9 fallin# on t;e 9an lead to 9ra9?in#.2nti9orrosion and in;i>itive 9oatin#s are >ein# proposed or

9onsidered for lon#-term performan9e.

+.& SCC PREVENTION UNDER INSULATION

8eep t;e insulation drle 9;loride 9ontainin# insulations.

2ddition of odium Metasili9ate as an CC in;i>itor to t;e

insulation at a minimum 9on9entration of ten times t;e C;loride9ontent.

(or maBimum prote9tion Metasili9ate is painted on vessels or pipin#

>efore installation of in;i>ited insulation. Cataluild epoB< paints up to 1!! !C.

Catalase 9oatin#s upto $!! !C.

);ese 9oatin#s are more effe9tive on sand>lasted surfa9e.

Prote9tion of t;e vessel or pipin# :it; or 2luminum foil under

insulation. It is effe9tive >et:een !-!!C. );e aluminum foils are

;o:ever first atta9?ed >< 2l?aline lea9; :ater from insulation and;en9e needs to >e periodi9all< rene:ed.

Pa#e of 1$%


67/129


IndianOil


Pa#e 0 of 1$%


68/129


IndianOil


,.0 STRUCTURED PAC'ING PRO-LEM IN COLUMNS

,.1 P#ENOMENA

tru9tured pa9?in# failure ;as >een eBperien9ed in LVO e9tion of

Va9uum Column of Mat;ura Refineret:een t;e pa9?in#. Durin# runnin# t;ere is no pro>lem.3e9ause (e-sulfide is purns, if dr< on9omin# in 9onta9t :it; air after t;e 9olumn is opened. )o avoid t;epa9?ed 9olumn is dren9;ed :it; 9opious amount of :ater to flus; outt;e entrapped sulfide prior to openin# also similar failure ;as >eenreported resultin# in >endin# up t;e 9olumn. Purns inpresen9e of oBution of flus;in# :ateror 9;annelin#, :;i9; leaves some parts un:as;ed, :;i9; later 9at9;esfire.

,. AREAS OF ATTAC'

tru9tured pa9?in# provided in t;e distillation 9olumns to improvedistillation are t;e pro>a>le areas of atta9?. );e lo:er void area of t;estru9tured pa9?in# also in9rease t;e possi>ilit< of su9; failure. );iste eBperien9ed :;ere pa9?in#s are used forremoval of 5$ in #as s:eetenin# plant.

,." MEC#ANISM

);e sulp;ur in t;e 9rud rea9ts :it; steel 9omponents and formspserved t;at stru9tured pa9?in# ;ad fallen do:n and 9aved-in, int;e LVO= 5VO se9tion. );e operatin# temperature of t;is @one is>et:een 161 !C to $0 !C. );e stru9tured pa9?in# is 1$!! mm ;i#;:it; $$ mm ;ei#;t of ea9; se9tion pa9?ed to#et;er. );e top and>ottom portion of a>out 1!mm ;ei#;t :as found inta9t :;ereas>rittleness :as o>served to:ards inner se9tion.

C;emi9al anal< :ei#;tF a#ainst !.!6G in t;e fres;sample. );is 9onfirms 9ar>on pi9?-up in t;e material, :;i9; 9an o99ur

Pa#e 6 of 1$%


69/129


IndianOil


at ;i#; temperature and is not eBpe9ted at t;e operatin# temperature;ere.

);e mi9ro-stru9tural o>servation on t;e 9ross-se9tion of fused pa9?in#9onsists of eAuiaBed ferrite #rains :it; presen9e of 9oarse 9ar>ide

pre9ipitates in relativel< ;i#;er Auantit< on #rain >oundar< as :ell as in#rains. Car>ide pre9ipitate formin# net:or?s alon# :it; t;e #rain>oundaries are also seen in t;e mi9rostru9ture :;i9; 9onfirms t;at t;epa9?in# ;as >een eBposed to relativel< ;i#; temperatures.

2nal


70/129


IndianOil


Provision of pressure #au#es a9ross stru9tured pa9?in# lae steamed out and :as;ed :it; ;ot :ater as

per eBistin# pro9edure.

4;ile underta?in# :ater :as; of t;e 9olumn, run all t;e pump >a9?

EIRF streams to ensure proper 9leanin# of t;e pa9?in#.

(ill up a99umulator vessel 1!-V- :it; :ater Ea>ove 6!GF and

slo:l< introdu9e >a#s of 8MnOE"!! ?#F from t;e upper man;ole.team ;ose ma< >e 9onne9ted at one of t;e vessel >ottom no@@leand steam is introdu9ed at slo: rate to a#itate t;e vessel 9ontent

and fa9ilitate dissolution of 8MnO into :ater. Ma?es;ift par#er:it; air ;ose 9onne9tion ma< >e provided inside t;e vessel toimprove a#itation. );is :ill ma?e $G: 8MnOsolution.

8MnOsolution :ill >e introdu9ed into t;e 9olumn and t;e flo: rate

;as to >e 9al9ulated >ased on t;e total volume.

(or Mat;ura refiner< Va9uum 9olumn t;e 8MnO :as; s9;eme :ill >eas follo:s-

);e flo: rate :ill >e Y 1! M"=;r as per follo:in# line-up Erefer'n9losure-1F.

1!V J 1!P$ J 1!'1 E>out $! M of "K dia temporar< pipin# :ill >e provided to 9onne9t

1!-'- to LVO CR 9ontrol valve 1$-(CV-".

4;ile introdu9in# 8MnO solution into 9olumn, fire:ater flo: :ill

also >e simultaneousl< maintained t;ruH adapters provided at t;e

lo9ation mar?ed 2K in 'n9losure-1.

Pa#e 0! of 1$%


71/129


IndianOil


(ollo:in# pumps :ill >e used for internal refluB Erefer 'n9losure-$F

Sl. 4o. P25p IR 3o -e7

1. 1$-P-$ LVO pump>a9?

$. 1$-P-0 LDO pump>a9?". 1$-P-% 5VO :as;@one

. 1$-P- trippin# traout !-! M"= ;r flo: :ill >e maintained t;ruH ea9; pump. 2s t;epumps :ill >e runnin# :it; :ater, ampera#e s;ould >e o>served :;ileloadin# t;e pumps so as to avoid trippin# of motors.

'nsure t;at t;e filters on pump >a9? ;eaders are on line to prevententr< of un:anted material into t;e pa9?in#.

2s 8MnOsolution passes, t;e pro:nindi9ates oBidation rea9tion.

Column >ottoms :ill >e drained t;ruH 1$-P- su9tion strainer to :aste:ater draina#e.

);e a>ove pro9ess ;as to 9ontinue till t;e effluent from 9olumn turns>a9? to purple. It is estimated t;at a>out 1 M) of 8MnO :ill >ereAuired for t;e :as; pro9edure and " >at9;es of solution :ill ;ave to

>e prepared in 1!-V- for t;e purpose.

On9e 8MnO:as; is 9ompleted, rinse t;e 9olumn :it; 9old :ater fora>out "- ;rs.

So5e I5po3a43 Poi43s

'nsure proper 9leanin# of t;e 9olumn :it; adeAuate steamin# and

:ater :as; >efore startin# 8MnO :as;.

4;ile openin# t;e 9olumn man;oles, start t;em from top :it; t;e

one after anot;er at a time interval of a>out $ ;rs. It is importantNO) to open t;e man;oles simultaneousl< at t;e top and >ottomsin9e t;is 9ould 9reate an air drau#;t t;rou#; t;e 9olumn and maustion of residual pe underta?en in t;e 9olumn, proper isolation

:it; as>estos >lan?ets to >e ensured to avoid fire splinter spreadin#

around.

Pa#e 01 of 1$%

7/24/2019 PR VE

Documents

PR VESSEL docuement