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DOCUMENT CODE MWP-WP-IMS-010 REV. # 00 REV. DATE 30-11-2012 PAGE 2 of 16

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1. PURPOSE

1.1 This Standard Procedure provides guidelines to be folloed for re!oval"

overhauling " calibration # testing and installation of $Pressure %elief &evices'

herein after called $P%&s' constituting of Safet( %elief )alves *S%)s+ and

%upture &iscs in order to,

nsure that the( operate ithin the set li!its for !echanical and

environ!ental safet( and integrit(.

nsure that the( protect the e/uip!ent # piping fro! over-pressuring

" vacuu!.

nsure that right safet( device is installed at right place.

nsure that an( un-authoried in their settings is not !ade.

stablish their inspection " replace!ent interval.

2. SCOPE

2.1 This procedure applies to inspection repair calibration # testing replace!ent

and docu!entation of all P%&s in Paarab ertiliers co!ple4. The ter! P%&s

also applies to )acuu! %elief )alves " )acuu! 5reaers for the sae of this

procedure.

3. RESPONSIBILITIES

3.1 General re!"n$l%e

3.1.1 Inspection nit is responsible to follo this procedure during inspections #

testing. The inspection engineer or his designated inspector is called as the

7uthoried Inspector. The 7uthoried Inspector shall have ade/uate

ROUTE PREPARED B& REVIEWED B& APPROVED B& RE'ERENCE

Na(e HAM)A NOUMAN )EESHAN NASIM ABDUL NASIR

Da%e

De*.+S*n. W.Shop ngr S8 W.Shop MM

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e4perience and " or certification as per 7PI 910 in perfor!ing P%&s

inspections.

3.1.2 7uthoried Inspector is responsible for docu!enting valve !aintaining

histor(" inspection records and schedules.

3.1.3 :peration &epart!ent shall issue notification to Maintenance &epart!ent for

re!oval of P%&s as per schedule.

3.1.; :peration &epart!ent shall get the aiver approved fro! the !anage!ent if

P%& cannot be released as scheduled.

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.1 Safet( re/uire!ent including but not li!ited to PTW PP scaffolding safet(

=S7 87>:P etc. as per Paarab ertiliers safet( rules # regulations shall be

co!plied ith.

.27ll necessar( safet( precautions hile oring at heights *e.g. Scaffolding+ shall

be taen.

.3 The %elief &evice shall be isolated de-pressuried and purged b( :perations

&epart!ent before re!oval for overhauling and calibration.

. DE'INITIONS

.1 Prere4Rele5n* De5/e6 These are used to protect e/uip!ent and

personnel b( auto!aticall( opening at predeter!ined pressures and preventing

the destructive conse/uences of e4cessive pressures in process s(ste!s and

storage vessels. 7 pressure relief device is actuated b( inlet static pressure and

designed to open during e!ergenc( or abnor!al conditions to prevent arise of

internal fluid pressure in e4cess of a specified design value. The device also !a(

be designed to prevent e4cessive internal vacuu!. The device !a(be a pressure

relief valve a non-reclosing pressure relief device or a vacuu! relief valve.

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. Rele- 5al5e67 relief valve is an auto!atic pressure relieving device actuated b(

the static pressure upstrea! of the valve hich opens in proportion to the

increase in pressure over opening pressure.

. Se% Prere6 Set pressure is the gauge pressure at the inlet for hich the relief

valve has been ad?ust to open under service conditions.

.7C"l0 D--eren%al Se% Prere 8CDS96

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iv. Installed on fired pressure vessels.

7.2Cla II6 %elief devices that are installed on process feed and product strea!s in

clean service and non-corrosive strea!s.

7.3 Cla III6 %elief devices that are installed in non-process services.

:. 'RE?UENC&

:.1 The folloing intervals shall be folloed for n%al n!e/%"n of the %elief

devices,

a. Cla I6 1 (ear or less.

$. Cla II6 less than 3 (ears.

/. Cla III6 5ased on vendorAs reco!!endation and e4perience but shall not

e4ceed 9 (ears.

CLASSI'IC

ATIONCLASS4I CLASS4II CLASS4III

Installation a. Installed on e4tre!el(

corrosive services

b. Sub?ect to plugging due

to solids

c. @e installations here

there is no previous

e4periences or service

conditions are unnon

d. Installed on fired

Pressure vessels.

Installed on

process feed

and product

strea!s in

clean service

and non-

corrosive

Strea!s.

Installed on non-process

services

re/uenc(

of1 Bear or less Cess than 3 5ased on vendorAs

reco!!endation and

ROUTE PREPARED B& REVIEWED B& APPROVED B& RE'ERENCE

Na(e HAM)A NOUMAN )EESHAN NASIM ABDUL NASIR

Da%e

De*.+S*n. W.Shop ngr S8 W.Shop MM

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Inspection(ears e4perience but shall not

e4ceed 9 (ears.

:.2 The inspection interval of the class I %elief &evices *e4cept for %elief valves

installed on fired pressure vessels+ !a( be increased b( a !a4i!u! of 2

ti!es the current interval if on to consecutive interval inspection the device

pops at the set pressures and shos no indication of e4cessive

fouling"plugging. 7ccordingl( the inspection n%er5al !a( be increased up to a

!a4i!u! of 3 (ears.

:.3 The %elief devices on fired pressure vessels shall be tested ever( (ear.

8ot setting of %elief devices on fired pressure vessels shall be carried out hen

the %elief valve is installed after calibration.

:. The inspection n%er5al of the class II and class III %elief devices !a( be

increased b( a !a4i!u! of tice the current interval if on to consecutive

inspections the devices pops at the set pressures and shos on indication of

e4cessive fouling. 7ccordingl( the inspection interval!a( be increased up to a

!a4i!u! of 10 (ears.

:. The inspection -re@en/, shall be increased in the folloing case,

a. or %elief device that has set pressure of !ore than ;19 Pag if it pops

at !ore than 9E of the set pressure during pre-test.

$. or %elief device that has set pressure up to ;19 Pag if it pops at !ore

than 20 Pag of the set pressure during pre-test and

/. If inspection indicates that the %elief devices is heavil( fouled or tuc.

In such cases the inspection interval shall be reduced bac to the

previous successful interval or F of the current interval.

ROUTE PREPARED B& REVIEWED B& APPROVED B& RE'ERENCE

Na(e HAM)A NOUMAN )EESHAN NASIM ABDUL NASIR

Da%e

De*.+S*n. W.Shop ngr S8 W.Shop MM

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:.7 %upture disc should be replaced on a regular schedule ith a to (ears

!a4i!u! period unless e4perience shos that a longer ti!e period is

acceptable. Shorter and"or longer ti!e periods !a( be acceptable based on

e4perience and !anufacturer reco!!endations.

:.: 7n( device that is !ore than 3 !onths overdue shall receive a revie and ritten

authoriation for continued operation fro! :peration &epart!ent Manager. 7n(

device that is !ore than 6 !onths overdue shall receive revie and ritten

authoriation for continued operation b( the Heneral Manager *:peration+. 7

defer!ents obtained shall be !aintained in the histor( file of the %elief deviceand its cop( shall be sent to Maintenance Planner.

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G.2.2 Maintenance &epart!ent shall cover the !ating flanges of e/uip!ent"piping

to prevent entr( of foreign !atter.

G.2.3 )alve shall be transported in the upright position to prevent internal

co!ponent da!age. lange faces and threaded connection should be

protected.

G.2.; Maintenance &epart!ent shall arrange to transport and deliver safet( relief

valve to repair organiation *in-house or outside plant pre!ises+.

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G.3.9 7s soon as the Safet( %elief valve is re!oved its general conditions shall be

recorded. Maintenance &epart!ent shall infor! Inspection nit before pre-

testing of the valve for perfor!ing visual inspection before atte!pting the $7s

%eceived Pretest' and all the observations such as corrosion scaling

deposit and other obvious da!ages shall be recorded in the or! $Pressure

%elief )alve

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G.;.6 The blo don loc nut *ring+ is loosened. The blo don ring is re!oved.

G.;.D The nole is re!oved. The disasse!bled parts are inspected and if an(

foreign !aterial found accu!ulated is collected and reported to the

Worshop ngineer.

G.;.G The parts are than cleaned K the disc in inspected and then lapped in round

or figure of eight pattern to the sa!e a( the fe!ale seat i.e. nole is also

lapped.

G.;.J The condition of both the seats is checed through !agnif(ing glass ith

ade/uate lighting. 7s an added practice the seat # disc are both polished b(

using polishing paper *grade 0;+. The polished condition is then again

inspected b( !agnif(ing glass.

G.;.10 The ste! run out is checed. If the run out is 0.003 to 0.00D in the ste! is

considered to be used ithout straightening. :therise a ne ste! is !ade

as per inspection reco!!endation based on !anufacturing is used a

!aterial.

G.;.11 The clearance beteen guide and disc holder is recorded on the chec list.

The nole or disc if it is not available in spare is eld built up using satellite.

The disc and seat are then !achined and lapped and inspected.

G.;.12 The valve is then reasse!bled b( inserting the nole in the bod( and the

nole threads are tightened. The disc holder is asse!bled in the disc

holder. The disc holder is inserted in the guide. The ste! is tightened and the

blo don ring is put in position and the blo don ring is inserted in the

loest position the disc holder and the ste! asse!bl( is placed in the bod(.

Haset is inserted belo he guide. It is non as bod( gaset. The button

and spring is inserted. 5onnet gaset is inserted and then the bonnet is

placed on the valve bod(.

ROUTE PREPARED B& REVIEWED B& APPROVED B& RE'ERENCE

Na(e HAM)A NOUMAN )EESHAN NASIM ABDUL NASIR

Da%e

De*.+S*n. W.Shop ngr S8 W.Shop MM

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G.;.13 The 5onnet bolts are placed in the holes and tightened. 7d?usting scres are

tightened and bought into the sa!e level as per original chec list then ?a!

out is tightened and the PS) is !ounted on the test bench.

G.;.1; The blo don ring is set as per the set pressure and the PS) is then

popped. The PS) is then lea tested. If the nu!bers of bubbles e4ceed the

vendor reco!!endation for that particular t(pe then the PS) is opened up

and the disc and seat are re-lapped.

G.;.19 When the PS) !atches the vendor reco!!endation for lea test and there

is an audible popping sound the PS) technician calls the inspector for

itnessing.

G.;.16 The pop test and lea test are repeated and verified b( inspection. If there is

proble! of resetting the blo don ring is read?usted. The loc nut is placed.

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PS) is installed on the test bench and blo don ring is ad?usted. Then the

PS) is popped and folloed b( Cea test.

G.;.1J PS) is inspected and if : the

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G.;.29 The asse!bl( starts ith the $:-ring' being placed on blo don rod. The

disc is then placed on the blo don rod and secured on the blo don rod

ith the help of set scre.

G.;.26 The liner is inserted in the pilot bod(. The shuttle is then placed in the liner.

$:-ring' is placed on the shuttle. The seat retainer is placed on the shuttle.

Ciner :-ring is placed on the liner. The shuttle seat is placed on the liner :-

ring.

G.;.2D The nole is placed on the shuttle seat. $:-ring' is placed on the nole.

&isc seat $:-ring' is placed on nole. Then the guide is placed on the

nole $:-ring' inall( the 5lo don rod is placed in the asse!bl(. Then

the button is placed on the disc. Then the spring is placed on the button.

Then the top button is placed on the spring. The bonnet is tightened on the

pilot bod(.

G.;.2G The ad?usting scres are tightened. Then a tube is placed on the blo the

don rod and then the self-locing out is tightened.

G.;.2J The pilot bod( asse!bl( starts ith the Sleeve $:-ring' is placed on the

sleeve and then the sleeve is inserted in the pilot bod(. The piston is fitted

top and botto! and botto! $:-ring'. Then the seat is tightened on to the

bod(.

G.;.30 This co!pletes the pilot asse!bl(. The pilot is placed on the test bench and

then it is popped and then its reseating is checed. If the pilot resets as perset pressure the pilot is considered to be : otherise the $:-rings' are

checed and replaced if found da!aged or scored.

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proof either alu!inu! or S.S.+. T(picall( the tag plate should indicate unit

designation identification nu!ber e/uip!ent nu!ber set pressure"

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J.2.; Se/%"n VIII6 %ules for construction of pressure vessels.

>.3NBBPVI

J.3.1 @ational 5oard for 5oiler and pressure )essel Inspection.

1. 'ORMS

1.1 P%SS% %CI )7C)