api-rp 1110 1991 recortada

7/23/2019 API-RP 1110 1991 Recortada

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S T D A P I I P E T R O R P

L L L O E N G L

L777 m 0732270 0 5 b l l b l l b L L L

m

Pressure Testing

f

Liquid

Petroleum Pipelines

PI RECOMMENDED PRACTICE 1110

FOURTH EDITION, MARCH 1997

Strategiesf i r Today s

Environm ental Partnership

American

Petroleum

Institute

merican Petroleum InstituteYRIGHT American Petroleum Instituteensed by Information Handling Services

7/23/2019 API-RP 1110 1991 Recortada


Pressure Testingof Liquid Petroleum Pipelines

1 Scope

This recomm ended practice covers the pressure testing of

new and existing liquid petroleum pipelines. It recommen ds

minimum procedures to be followed, sugg ests equipment to

be used, and points out factors to be con sidered during the

pressure esting of liquid petroleum pipelines. Th is reco m-

mendedpractice does notaddress owpressurepneumatic

testing.

This recommen ded practice suggests procedures hat are

based on sound eng inee ring udg men t, but certain govern-

mental requirements may differ from the procedures et forth

in this recomme nded practice. Suc h requirements should

be

fulfilled because this recommended practices not intended to

supersede

or

override them.

Please be advised hat hisdocument does notpreclude

requalifying a line for liquid service under the provisions of

ASME 31.8, Appendix N (as provided for

49

Code

of

Fed-

eral Regulations

195.5

(a) 1)

(I.)).

2 ReferencedPublications

Unless otherw ise specified, the m ost recent ed itions of

the following standa rds, code s, and specifications shall,

to the extent specified herein, form a part of this stan-

dard.

ASME'

B 3 1.4 LiquidTransportationSystems fo r Hydrocar-

bons Liquid Petroleum G as Anhydrous Ammo-

nia and Alcohols

D O T

Research and Special Programs Adm inistration

(Title 49 Code o FederalRegulations Part

195)

3 PressureTesting of iquid Petroleum

Pipelines

3 1EFINITION

In pressure testing, internal pressure above the normal or

maximumoperatingpressure is applied

to

asegment of

pipeline, under no-flow conditions, for a fixed period of

time. A liquid test medium is used to apply the internal pres-

sure.

American Society of Mechanical Engineers, 45

East

47th Street, New

York

New

York

O017 .

US. Department of Transportation. The Code

of

Federal Regularions is

availableromhe U S . GovernmentPrinting Office, Washington, D.C .

20402

3 2 CODE REQUIREMENTS FOR PRESSURE

TESTING

3 2 1 New Construction and the Replacement of

Existing Pipelines

Th e pressure testing of newlyconstructedpipelinesand

replaced segments of existing pipelines should be performed

in

accordan ce with ASME B3

1.4,49

Code of Federal Regu-

lations Part

195

and any other applicable governmental regu-

lations.

3 2 2 Qualification of Existing Pipelines For a

Higher Operating Pressure

The qualification of existing piping systems or an operat-

ing pressure higher than the previously established operat-

ing pressure shouldbe performed in accordance with ASM E

B31.4, 49 Code of Federal Regulations Part 195 and any

applicable governmental egulations.

3 2 3 Requalification of Existing Pipelines for

Continued Operation at the Current

Operating Pressure

The requalification of existing pipin g system s for con-

tinuedoperation at the previouslyestablishedoperating

pressure should be performed in accordance with ASME

B 3 1.4, 49 Code o Federal Regulations Part 195 and any

applicable governmental regulations.

3 3TESTMEDIUM

A p ressure test should be con duc ted with water; however,

liquid petroleum having a Reid vapor pressure' less than 7

pounds per square nchabsolute may

be

used as the est

medium

if

all of the followingconditions are met:

a. The pipeline

or

piping segm ent to be tested is not part of

an offshore pipeline or offshore piping facility.

b. Th e pipeline or piping segment to be tested is not located

where a release could adversely impact any environmentally

sensitive areas.

c. The pipeline or piping segment tobe ested (rated for

operation above

275

psig) is o utside of cities and/or other

highly populated areas.

d. Every building located outside

f

the owner's piping facility,

but within

300

feet 92 meters) of the pipeline or piping seg-

ment o

be

tested, sunoccupiedwhile he estpressure s

greater than

or

equal to a pressure that produc es a hoop stress

of 50 percent of the pecifiedminimum ield trength

(SMYS).

?Reid vapor pressure is defined

as

a liquid s true vapor pressure at 100°F.


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API RECOMMENDED

RACTICE

110

e. The pipeline or piping segment to be tested is kept under

regular surveillance by pipeline personnel equipped with por-

table radios

or

similar equipment to provide continuous com-

mu nicatio n with the person in charge.

f. Suitable contingency response equipment andpersonnel

for spill cleanup are strategically placed near the pipeline or

piping segment to be tested.

g. Test procedures meet all applicable local, state, or federal

government regulations.

3 4 EQUIPMENT AND MATERIALS FOR A

PRESSURE

TEST

Equipm ent for a pressure test should b e properly selected

and be

in

working order.The mea surement equipment should

be appropriate for the pressures expected du ring the pressure

test. The following equipment may be required for a pressure

test:

a. A high-volum e pump that fills the line, ensures adequate

pressure to overcome head, maintains sufficient velocity o

move debris, minimizes interfaces, ensures turbulent flow,

and keeps any pigs moving.

b. A test medium supply line filter that ensu res a clean test

medium.

c .

An injectionpump hat introduces corrosion inhibitors,

leak detection dyes or gases, or other che mica ls into the test

segment if their use is desired.

d. A meter for measuring line fill or a comparable mean s of

measuring it.

e. A variable spe ed, positive d isplace men t pum p that pres-

surizes the line to a suitable or appropriate level that exc eeds

the specified test pressure. The pump should have a known

volumeper stroke and should be equipped with a stroke

counter.

(A

constant-speed pump with a variable flow rate

control may be used in lieu of he abov e if he liquid test

medium injected into the pipeline is measured d uring pressur-

ization.)

f. A relief valve. Th is may be included to prevent overpres-

sure of the test segment during both the pressurizing activities

and the test.

g.

A

portable tank r transport into which excess test

medium can be discharged and from which m ake-up volumes

can be drawn.

h.

A

pressure sensing and d isplay device that has the pressure

range and increment divisions necessary to indicate antici-

pated test pressures.

i A deadweight teste^ or an equivalent pressure sensing

device that is capable of m easuring in increm ents of less than

or equal to one

(1)

pound per square inch 6.7 kilopascals).

The

device should have a certificate of calibration that is not

4All

references to “deadweight tester” in this document includ e m y equiva-

lent pressure sensing device.

more than one year old at the start of testing or calibrated

in

accordance with the manufacturer’s recomm endations.

j. A continuous-recording pressure measurement device

(such as achart recorder) that provides a permanent record

of

pressure versus time. This device should be calibrated imme-

diately before each use (using the dea dweight tester) or cali-

brated in accordance withhe manufacturer’s recom-

mendations.

k. A test medium temperature sensing and display instrument

that is properly calibrated to a range suitab le for anticipated

test temp erature s and can be read in increm ents of no ess

than O

1

OF (0.05”C ).

1 A continuous-recording emperature measurement device

that provides a pe rmanent record of pipeline temperature ver-

sus time.

m. Facilities that protect all instrumentation from weather

extremes.

n.

Equipm ent that indicates ambient temperature.

o. Electronic pressurehemperature monitoring and recording

systems that ssist in the ana lysis of test da ta. Such sy stems can

be used in lieu of the comp onents listed above provided that

the individual pressure sensors included in the systems have a

level of sensitivity and can be field calibratedn

a

manner simi-

lar to those instruments listedn Items a through m above.

p. Pigs, scrapers, spheres, and similar devices that clean the

test segm ent and facilitate the removal of air from the line.

q. Temporary manifolds and connections, as needed.

r. Equ ipme nt, mate rials, and fluids that are needed to intro-

duce and displace the test medium from the est segments.

s . Comm unication equipment that

is

adequate for coordinat-

ing test activities.

t. Equipment that isolates line segments for leak de tem ina -

tion and facilitate s repair.

u. Replacem ent pipe, valves, gaskets, and so forth, to replace

those that fail dur ing pressure test.

CAUTION: If freeze plugs are used to isolate line segments,

special handling techniques should be used to ensure person-

nel safety. Con sideratio n should be given to nonde structive

examination for flaws, toughness, and he ductile-to-brittle

transition temperature when selecting the joint for the freeze.

3 5 TESTPLAN

When planning a pressure test, the following factors should

be considered:

a. The maximu m operating pressure anticipated for the life

of the facility. Tests should normally be planned

so

that any-

where in the test segment the pressure level does not produc e

hoop stress near

or

above the SMYS. If lines are tested at

pressures that develop a hoop stress, based on nominal wall

thickness, near the SMYS of the pipe, special care shall be

taken to prevent the pipe from overstraining. Close examina-

tion of engineering documentation, such

as

mill test reports


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S T D = A P I / P E T R O R P L L L O E N G L L777 m 0732270 0 5 b 4 b 5 4

2 7 8

PRESSURE

TESTINGF LIQUID

ETROLEUM

PIPELINES

and field maintenance reports, can nsu re the minimu m grade

and wall thickne ss of pipe i n the seg me nt. If internal inspec-

tion tools surveys were cond ucte d, the data should be care-

fully reviewed. For tests at pressure levels near the SM YS ,

consideration should be given to keeping a pressure-volume

(P-V ) plot during pressurization o prevent yielding of the

pipe. The effects of transporting water through the pipeline

upon the oper ating and sta tic pressure profiles sho uld be con-

sidered.

b. C ompo sitions of the pipe and piping comp onents in the

test segment. Pipe and piping com pon ents should be located

by their size, wall thickness, grade type, internal design pres-

sure, and elevation profile.The comp onent hat controls max-

imum test pressure should be identified.

c. The shell pressure and flange rating and the location of all

pipeline valves, equipm ent, air vents, and other connection s

to the segment that will be exposed to the test pressure. Test

pressure shall not exceed the manu facturer’s recommended

maximum allowable test pressure.

d. The anticipated emperature of the est me dium , atmo-

sph ere, and ground and the temperature stabilization period

of the test medium. Particular care shou ld be taken to prevent

freezing of exposed iping uring oldweather.Large

am oun ts of exposed piping can result

in

large temperature-

related pressure chan ges, making a stable test difficult.

e. The est medium’s primary and makeup sources and any

inhibited or other treating requirements. State and local codes

should be reviewed to determinef regulatory requirements for

obtaining source water and for disposing of test water exist.

f. Sam pling provisions to ensure (and to docu ment) water

quality before the line is filled and again before ultimate dis-

posal occurs.

g. Location s and requireme nts for test medium disposal.

h. Profile and alignme nt drawing m aps.

i

Safety precautions and procedures for personnel who per-

form the test.

j .

A

delineation of the respo nsibilities of various personnel

in

the testing organization, especially those who prepare doc-

umentation.

k. Precaution s and proced ures to minim ize risk to the public

and he environm ent, especially when a test medium other

than water is to be used.

1

Notification of p roper au thorities, agen cies, and potential

emergency response personn el, as well

as

landowners along

the right-of-way.

m. A plan for dealing with failures, including equ ipm ent, per-

sonnel, materials, and inspection.

n. Methods for preserving the fractured surfaces on the failed

specim ens of pipe.

o.

Pressureproof test andpressure eak test acceptanc e

criteria.

p. Procedures and materials used for assisting in leak detec-

tion and locating, such as dyes or gases.

q.

Potential bleed location.

3 6

TEST

PROCEDURE

Before testing begins, a pressureest rocedure with

explanatory notes and data should be prepared. This detailed

procedure should provide the following:

a.

A

diagram indicating the length s, elevation s, and locations

of the test seg me nts, including any tested piping ma nifold s,

and set-up of test equipm ent. Locate the taps for the pressure

recording devic es on the pipeline. Do not locate the taps on r

near the high pressure

f i l l

piping. The taps sho uld be located

several feet from the high pressure pum p injection point in

order for the readings to be accurate during the pressurization

process.

b. Th e test medium to be used, fill rates, and the line f i l l vol-

umes for filling and at test pressure.

c. Methods for cleaning, decom mission ing, filling,nd

recommissioning est segments.

d. Meth ods for pressurizing the test segm ents. These meth-

ods shou ld indicate the locations of

the

injection points with

respect to reco rding locations and sho uld provide the speci-

fied minimum and maximum test pressures.

e. Methodsfor isolating the est segm ents. These metho ds

should indicate which blinds and plugs o install, valves o

remove, and cathodic rectifier systems to be de-energized.

f . The minimum test duration for test segments.

g. Methods for removing and disposingof the test medium.

h. Safety precautions and procedures.

i

An identification of and a specification or heweakest

link or

controlling component

in

the test section.

The specified est pressure s he minimum est pressure

that should be applied to the most elevated point in the test

segm ent. This elevation is not necessa rily that of the dead-

weight tester; therefore,

i t

should be corrected

for

eleva-

tion differe nce betw een the pipeline and deadw eight tester.

The minimum test pressure should be in accordance with

ASME B 3 1 4 and 49 Code

o Federal Regulations

Part 195.

A detailed an alysis of the profile to determine what the

pressures will be during the test should be performed so

that the pipeline will not be overpressu red at points that

are at ow eleva tions. Sinc e the test pump and recording

equipment are not necessarily at the highest elevation, test

personnel should be provided with precise target pressures

for the elevation at the pum p and recorders.

3 7 LINE FILL AND CLEANING

The line fill operation shouldperform wo unctions-

clean the line and introduce the necessary test me dium into

the test seg me nt. It should be noted that pigging oper ation s

will not normally remove all hydrocarbon s from the piping

segm ent. B efore the actual line filling operation, it is advis-

able to run a sizing pig, caliper or deformation

tool

inan

effort to identify any geometric abno rma lities that may exist

in

the line prior o the test. In addition to running a sizing pig,


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4

API

RECOMMENDEDRACTICE110

consid eration should also be given to runnin g a batchltrain of

cleaning pigs to remove sedime nts, paraffins, and so forth,

from those pipeline segments that are not under a normal pig-

ging program.

The filling operationnormally utilizes several differen t

pieces of equipm ent, including the following:

a Large volume (relative to line size) f i l l pump.

b. Filter screens, if a nonmun icipal water sup ply is used o

filter out sedim entkon tamina nts.

c. Flowmeter.

d. Filling pig(s).

e. Portable tank.

The large volume fill pump should be sized such that the

fill pigs w ill travel at a speed that will m aintain a tight fit

of the pig and, depending on the terrain, reduce the risk of

the ntroduc tion of air or anothe rcompressiblemixture

behind the

fill

pigs, thus making a quality test difficult. A

minimum of 2 to 3 mph is asuggestedstartingpoint.

Unless the line

fill

is occurring with som e form of back-

pressure, as pigs ravel down the line and down a slope, the

weight of the column of fluid could cause the pig to travel

faster than the filling o peration would allow, thus introduc-

ing air

or

gas behind the pig.

If w ater is used as the test me dium , tsquality and

sourceshould be determ ined. Water that is not free of sed-

iment and acid may injure the pipe, valves, nd equipment,

and should not be used unless it is filtered and inhibited.

The possible deleterious effect f additives or inhibitorson

the processing of liquid petroleum tobe transported should

be investigated.

A flow meter should be placed

in

the line so that one can

mo nitor and maintain the design rate of

fill.

The meter will

allow the test personnel to make adjustm ents as necessary as

pressure builds and

fill

rates drop. It also assists in matching

the actua l fill volume with the calcu lated

fill

volume.

Record the fill medium temperature prior to introduction

into the line. This w ill aid in the determination of line stabil-

ity.

Pigs or spheres may be inserted to sepa rate the test medium

from the estofhe pipeline content. Locators maybe

inserted

in

the pigs to track them during the filling process

and to ensu re hat the pigs are where they need to be.

A

portable tank is used to make up the d ifference between

the actual w ater supply and the high volume fill pumps. This

may not be necessary if the fill pum ps have a direct supply,

such as a river.

Excavated segm ents should be backfilled insofar as practi-

cable before pressurization. The sensor of the recording tem-

perature device(s) should be installed so that it is in contact

with the pipeline at apoint where it has normal cover and at a

distance far enough back from the injection point

so

that the

effect of the exposed piping and make-up injection on tem-

perature is minima l. The backfill around the reco rding tem-

perature device sensor should be tamped. Insulate, if

appropriate, the capillary lines to the temperature recorder,

and install the recorder

in

an insulated box. Large centrifugal

pumps and storage tanks will affect the emperatu re of the test

medium. The temperature ofhe uriedine should be

recorded

until

the

pressure test is completed.

3 8 CONDUCTING THE PRESSURE TEST

3 8 1ressurization

Gen erally, the filling process is o mple ted using a high vol-

ume pum p. Pressuriz ation above this point is the scope of this

section.

Note: Personnel conducting the test should m aintain continuous surveillance

over the operation to ensure that it is carefully controlled.

The pressurization of the section of pipe to be tested begins

once the segment is

full

of fluid and the appropriate measures

have been taken to bleed any and all air or gas out of that sec-

tion;

in

other words, he section ispacked. Pressurization

involves bringin g the se ction of pipe to be tested up from the

static pressure after the

fill

proce ss to the desired test pres-

sure. The following equipme nt may be necessary to comp lete

this process:

a. High pressure positive displacem ent pumps.

b. F low meter and volume accum ulator.

c. Deadw eight pressure tester.

d. Tempe rature recorder.

e. Pressure recorder.

f. Portable tank.

Pressurization of the section should occur at a controlled

rate oavoid surging the ine. Pipe connections should be

periodically checked for leaks during pressurization. The flow

rate sh ould be m onitore d and ogged orpreparationof a

pressure-volume P-V plot, if applicable. Calculations indicat-

ing the amo unt of s quee ze fluid require d to go from the fill

pressure to the test pressure should be made prior to the test

and given to test personnel. This information aids

in

deter-

mining the tightness of the segment and assists

in

determin-

ing, along with the

P-V

plot, if leaks have occurred or if the

pipe has yielded.

Once

80

to

90

percent of the test pressure is reach ed, the

rate of pressurization should be reduced, especially when the

test is at or near 1 0 0 percent SMYS. Once the desired test

pressure is reached, the equipment should be stopped and iso-

lated from th e sectio n. At th is point, prior to the start of the

test, it m ay be desirable to have a stabilization period, which

would allow both the temperature and pressure to settle.

Note that pressure charts, sensors, and displays only show

an appro xima tion of the actual pressu re. The ch arts provide

proof of the continuity of the test. The d eadweight tester or

electronic equipment provides the actual pressureo e

recorded.


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PRESSURE TESTINGF LIOUID ETROLEUMIPELINES

5

Keep safety

in

mind at ll times Pipe maintained at

high pressure is dangerous. Test personnel should stand at a

safe distance from the test section or stand so that there is

something substan tial between them and the section being

tested.

3 8 2 TheTest

Period

When he estpressure sreached,pumpingshouldstop

and

all

valves and connections to the line should be inspected

for leakage. After inspecting for leakage, test personnel

should take the time to verify that the specified test pres-

sure is being maintained and temperatures have stabilized.

Wh en this verification procedure ha s been comp leted , the

injection p um p should be isolated from the test section. Th e

test period should begin after the injection pump has been

stopped, and the system has stabilized. The duration of the

test period should be in accordance with ASME

B3 1.4

and

49

Code

o

Federal Regulations Part

195.

Pressureand emperatureshouldbecontinuouslymoni-

tored dur ing the test, and all of the pressure readings should

be ecorded.Deadweight estercomparisonswithpressure

recorder readings should be made at the beginning f the test,

periodically during the est, and at he end of he est. The

results of the deadweight tester checks and temperature read-

ings should be recorded on the pressure and temperature logs

within at least 30-minute intervals. Weather chang es, such

as

the development of rain or clouds, that could affect the pres-

sure and temperature recording charts should be documented

on

the deadweight log. The volume or pressure

of

any added

or subtracted test medium should be documented on theead-

weight log,

as

well as the emperature and pressure at hat

time and be acco unted f or in the assessment of the results of

the pressure test.

Minor or gradual pressure changes during the test can be

a

result of residual air in the segm ent, temperature effects, or

leakshrough malldefects

or

loose lange connections.

Extending the test duration can demonstrate thatair and tem-

perature effects have been accounted for.

3 8 3

Pressure

Test Records

Personnel conducting a pressure test should keep a com-

plete rec ord of the test, including de tails of the test operation

andevents such as weathervariations, est ailures,bleed-

Offs, repressurizations, and so forth. Any failures that occu r

during the test shou ld be described in this record. The record

should indicate theexact location

of

each failure, describe the

type of failureand tscause,anddescribe hemethod of

repair.Pipe, ittings, or valveshat ail nd re eplaced

should be marked with their pipeline station location and the

pressure at which they failed. When appropriate, such materi-

als should be preserved by the operator for failure analysis.

Records of pressure ests are to be maintained by the

operatoro omply with theequirements of ASME

B31.4, 49 Code of FederalRegulationsPart 195, and

all

otherapplicablegovernm ental egulations. Test records

may includ e, but are not necessarily limited to, the follow-

ing (Appendix

A

contains sample forms.):

a. Continuous pressure versus ime record with appropriate

information listed

on

it (see Figure

A-I) .

b. Continuous temperature versus time record with appropri-

ate information listed on

it

(see Figure A-2).

c. Deadw eight calibration certificate.

d. Test plan (se e

3.5).

e. Pressure test record and certification (see Figure

A-3)

that

includes the following:

1

Qualification calculations (see Figure

A-4).

2. Pressure and temperature log (see Figure A-5).

3. Record of th e failures that occu rred during the test and

the reason for the ailures (see Figure A-6).

3

Profile of the pipeline that shows the elevation and test

sites over the entir e length of the test section, if elevation

differences in the est section exceed 1 0 0 feet (30 meters).

5. A drawing of any facility piping tested and the limits of

the test. The se test records should be signed y the respon-

sible parties and retained for the ife

of

the facility

or

until

new test records supersed e them.

3 9DISPLACEMENTOFTESTMEDIUM

A carrier may choo se to displace est water with iquid

petroleum, air, or inert gas. If air or inert gas is to be used,

careful consideration must be given to the amount

of

energy

stored in the compressed gas.

Test medium may be displaced with spheres, squeegees, r

other pigging devices. When water is displaced,

it

should be

disposed of naccordancewith all applicablegovernment

environmental regulations. It should be noted, though, thatll

of the estwater may have

to

bestoreduntilpermitsare

received for ultimate d isposal. Product qualityor internal cor-

rosion con trol requirements may dictate that pipeline drying

regimen be conducted after the water

s

displaced.


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S T D I A P I P E T R O R P LLLO ENGL L 7 7 77 3 2 2 7 0 0 5 b q b 5 9 87T

m

~~

1

APIECOMMENDEDRACTICE 1110

S MPLE PRESSURE TEST

RECORD ND CERTIFIC TION

Test section

Date

~~~~ ~~ ~

2ompany System

Description rom to

New construction

Requalification Replacement or relocation

O

Pipeline O Station O

rest medium: water Other Inhibitor

Design data code:

O

831.4 B31.8 Appendix N Other

Pipe design data

Specification

Design

all

esign

eld joint

and grade

Comments

ressure

MYS

hickness

D

actoractor

~~~ ~~ ~ ~

Pressure test:

~ ~ ~~ ~~ ~

Test pressure should be as follows:

Minimum atigh point SMY Maximum at low point

o SM\

Elevations: pointigh point DWT

Qualifications:

Date of test: Duration of test

Testing and recording witnessed by Date

Company

Title

Company representative

Title

Testing pressure:

Maximum at low point for SMYS

Minimum at high point for SMYS

Qualified to operate at for SMYS

Report checked by Date

Approved by Time

Testing company

4ttached documents:

Pressure record Pressure and temperature lo

Temperature record

Test instrument calibration data Sketch or diagram

Qualification calculations

Profile Failure records

Zomments:

Notes:

OD = outside diameter,SMYS = specified minimum yield strength,MY = specified minimum yield, WT =deadweight tester.

For test sections containing more than one

ype

of pipe, the maximum test

ressure

at low point and minimum test pressure at high point and

resultingSMYS need tobe calculated for eachype of pipe.

Figure A- Sample Pressure Test Record and Certification

YRIGHT American Petroleum Institute

api-rp 1110 1991 recortada

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