~PIPEUNE MAINTENAI«:E W8..DING PRACTaS 9

6" (152 mm) minimum

1,4. (3.17-mm)maximum radius onal! comers

tApproximately1. (25.4 mm)

.

v Wall thickness

N«es:I. The specimen may be machine or oxygen cut.2. The weld reinf~t shall be removed from 00th faces flush with the surface of tbe specimen.3. The specimen may be fIancned at room temperatwe before tcsting.

Rgure 7-Root-Bend- and Face-Bend- Test Specimens-Groove Welds

,!!;...

Notes:1. Radius ofplunger: A=I}; inches (44.45 millimeters): radius ofdie: B=~. inches (58.74 millimeters): width ofdie: C=2 inches (50.8 millimeters).2. Figure is !10( to scale.

Figure 8-Jig for Guided Bend Test

10 API RECOMMENDED PR4CTK;E 1107

.

\ I\ I

\,.--~

Wall thK:kness

"

'/Í" (3.17-mm) maximum

j I ~ radius 011 all ~mers

I~-¡- t. Wldth 01

1h" (12.7 mm) ~ specimen

6. (152 mm) minimum .1

t

'-1-

'- Wall th~ess

then machined 01' ground srnooth 10 a :l:-iIK:h (12.7-millimeter) widdl. Thccut surf~es shalI be smoodl and parallel3. Thc specimen may be flattened at room temperanae.

Notes:

I. The weld reinfon:ement shall be removed from both f~ f1ush with the

surface of the specimen.

2. The specimen may be machine cut to a ~~ (12.7-millimeter) width. CX"

it may be oxygen cut to approxjmare1y a 'I.-~ (19-mil1imeter) width aDd

Figure 9-Side-Bend- Test Specimen-Groove Welds

weld soundness. The use of optic devices or dye penetratingmaterials is not necessary.

2.6.6.3 Acceptance Criteria

enough to assure d1at the welds can be examined. For eachspccimen, at least one face of each cross section is to beground smoom and etched with a suitable etchant. such asammoniwn persulfate or hydrochloric acid. to give clear def-inition to the structure of the weld.

In lieu of taking specia1 specimens for macro examina-tions, the nick-break specimens may be used. Nick-breakspecimens used for this purpose are to be examined beforethey are nicked.

A visua1 examination of the cross section of the weldshould show d1at it is completely fused at the root and free ofcracks. The fillet weld should have leg lengths that are atleast equal to the lengths specified in the proceduxe specifi-cation and should not deviate in concavity or convexity bymore than X6 inch (1.59 mi11imeters). The depth of the under-cutting shou1d not exceed ~ inch (0.79 millimeter) or 12Xpercent of the piping wa1l thickness, whichever is sma1ler.

2.6.6.2 Method of Examination

The cross section of tbe weld is to be visUally examinedwith lighting that will sufficiently reveal the details of the

Note: Smooth and etCh atleast one face of each weld specirnen cross scction with suitable etchant to give a cleardefmition to the weld stnICtt1Ie.

~E ~ WEl.DtNG PAAcrx;es "

SECTION 3-WELDER QUAURCATION

qualification of a welder is to be conducted in the presenceof a company representative.

3.2 Welding of Test Assembly

A welder qualifying in accordance with this recommended practice is to weld a test assembly simila:i to the oneshown in Figure I or II.. The essential variables associatedwith maintenance welding procedure qualification andwelder qualification are not identical. Welder qualifica.tionis a function of certain essential variables which are setforth in 3.3.

3.1 Purpose

Tbe welder qua1ification test is meant to detennine

whether a welder has the ability to make sound welds using

a previously qualified welding procedure. Before any main-

tenanc;e welding is perfOmled. a welder must be qua1ified in

accordance with the applicable requirements of 3.1 to 3.6 of

API Standard 1104 or 3.2 to 3.5 ofthis .-m...xIed prac-

tice. We1der qualification f(X circwnferential butt we1ds shall

be in accordance with API Standard 1104.

A welder who successfully welds a test assemb1y for a

procedure qualification test is qualified for that procedure

within the range of essential variables which govem welder

qua1ification. Before starting the qua1ification tests, the

welder should be a1lowed reasonable time to adjust the weld-

ing equipment used in the test. The welder is to use the same

welding technique and to proceed with the sarne speed that

he will use if he passes the test and is peImitted to weld. The

3.3 Essential Variables for Welder

Qualification

If any of the following essential variables OCCUf. the

welder using the new procedure is 10 be requalified.

.

Nace: This test ~iri(X1 qualifies d)e we1der for a1I ~itions. Tests may be perfom1cd in odIer positions wbiclI will

qualify d)e welder for that ~ition only.

Figure 11-Welder Qualification Test Assernbly

API RECOMMENDED PRACnCE 1107

~

3.5.2.1 Tensile- Test AcceptanceCriteria-Groove Welds

Each tensile-test specirnen shou1d meet the acceptance cri-teria for tensile tests, which are provided in 2.6.2.2. lf anyspecimen fails to meet those criteria. the welder is disquali-

fied.

3.5.2.2 Nick-Break- Test Acceptance Criteria

If any nick-break-test specimen shows defects exceeding

those allowed by the acceptance criteria for nick-break tests

provided in 2.6.3.3, the welder is disqualified.

a. A change from one welding process or combination ofprocesses to any other welding process or combination of

processes.b. A change in the direction of welding from vertical up tovertica1 downorvice versa.c. A change in the filler metal classification from eitherGroup 1 or Group 2 to Group 3 or from Group 3 to eitherGroup 1 or Group 2 (see Tab1e 1).d. A change in the diameter group. A welder qualified onpipe baving an outside diameter of less than 12Y. inches(323.8 millirneters) shall be qualified for all diameters lessthan or equal to the diameter used in his qualification test. Awelder qualified on pipe having an outside diameter ofgreater than orequal to 12Y. incbes (323.8 mil1imeters) shallbe qualified on all pipe diameters.e. A change in the DOOlinal material wall thickness frorn onegroup to another. Some suggested thickness groups are asfolldws:

1. Less than ~6 inch (4.78 millimeters).2. From ~6 incb to ~ inch (4.76 rnil1imeters to 19.05 mil-

limeters).3. Greater than ~ inch (19.05 millimeters).

Visual Examination

~

The weld is to present a neat. workmanlike appearance.Unóercutting adjacent to the final bead on the outside of thepipe should not exceed a depdt of Yn inch (0.79 millimeter)or 12~ percent of the pipe wall thickness. whichever issmaller; there should not be more than 2 inches (50.8 mil-lirneters) of undercutting in any continuous 12-inch (304.8-millimeter) length of weld or in one sixth the length of theweld, whichever is smaller. Failure to meet these require-ments is sufficient cause for e1iminating additional testing.

Performance QualificationTests-Destructive Testing

SAMPUNG OF TEST WELDS

T

R8orS8

N8 II

FBorS8 I I

N'

81

Test specimens are to be cut from the test assembly loca-

tions shown in Figure 12. The type and minimwn number of

specimens are given in Table 3. Before testing, test speci-

mens are to be air cooled to ambient temperature.

TENSILE-, NICK-BREAK-, ANDBEND-TESTPROCEDURES

c::::-1The tensile-, nick-break-, and bend-test specimens for the

procedure qualification tests are to be prepared. and the testsare to be made as described in 2.6.2 through 2.6.5. The ten-

sile tests may be omitted; if they are omitted, the specimens

designated for the tests are to be subjected to the nick-break

Note: T=tensile; RB=root bend; FB--face bend; NB=nick break; SB=sidebend. '-

-

PlPEUNE MAwrENAta WElDING PRACT1CES 13

TabJe 3- Type and Number of Test Specimens-WeIder Qualiflcation l\,st

Number of Specimens

Wcld

TypcNickB~

R00[Bend

Face

~

SideBendTensile ;)¡;J

WallThickness

l4'

l4'

~ 44

44

>~ inch 2

"Al the owner's option. these specimens may be subrniued !O the ~section test (see 2.6.6) befo~ ~y aresubmitted !O the nick-break testo

(í;teriasection-test specimen does not meet th~ ¿.~í.;':Pi:2lh

in 2.6.6.3, the welder is disqualified.

3.6 Retest

If, in the opinion of d1e company, tllt faillU'e of 4t \ \;:der to

pass the test was because of unavoidable conditions or con-

ditions beyond his control, the welder may be given a second

opportunity to qualify. No further retests need to be given

until the welder has submitted proof of subsequent welder

training that is acceptable to the company.

3.5.2.3 Bend- Test Acceptance Criteria-GrooveWelds

If any bend-test specimen shows defects exceeding thosea1lowed by the acceptance criteria for root- and face-bendtests provided in 2.6.4.3 or for side-bend tests provided in2.6.5.3. the welder is disqualified. It should be noted. tl1ough.that a weld in high-test pipe (API Specification 5L. GradesX42 and above) may not bend to the fu1I U shape. A weld inhigh-test pipe is considered acceptable if the cracked speci-men is broken apart and its exposed swface meets the nick-break-test acceptance criteria in 2.6.3.3.

If a bend-test specimen fails to meet these criteria and. inthe opinion of the company representative. is not representa-tive of the weld. the bend-test specimen may be replaced byan additional specimen cut adjacent to the one that failed.The welder is disqualified if the additional specimen alsoshows defects exceeding the specified 1inñtS.

. 3.7 Records of Qualified Welders

A record is to be made of the tests given to each welder

and of the detailed results of eacb test. This record should be

developed to suit the needs of d1e individual c001pany and

should be sufficiently det4Üled to demonsn'ate that the qua1-

ification test embodied tbe various requirements prescribed

by this recommended practice. A list of qualified welders

and the procedures in which they 8IC qualified is to be main-

tained. A welder may be required to requalify if there is aquestion about his ability. .

3.5.3 MACRO-SECTlON- TEST PROCEDURES

ANDTESTACCEPTANCECRITERIA-FJLLET WELDS

The macro-section-test specimens are to be prepared andexarnined as described in 2.6.6.1 and 2.6.6.2 If any macro-

SECTION 4-SUGGESTED MAINTENANCE WELDING PRACTICES

4.1 General

For the pipe welding to be in accordance with this recom-mended ~ce, the .welding is~ ;~",~~b>:.e~ -.welders usmg quallfied piocedUIeS~aces to bewelded are to be smooth; unifonn; and free of laminations.te3rs, sca1e, slag, grease. paint. and other deleterious ~which might adversely affect the welding. The joint design isto be in accordance with the welding procedure to be used.

Before welding on a piping system which is being or hasbeen used for the compression. pumping, ttansmission, ordistribution of crude petroleum. petroleum products. or fuelgases, welders should consider aspects that affect safety.such as operating pressure. flow conditions, and wall thick-

ness at the location of the welding. All welders performingrepair work sball be familiar with the safety precautions as-sociated with cutting and welding on piping that contains orhas ~tained liquid petrolewn or fuel gases.

1SartrCUlar considemtion should be given to the fillet weldused to join a sleeve to a carrier pipe because the fillet weldis prone to Wlderbead or delayed hydrogen cracking. Withwelds on pressurized and flowing piping systems, successhas been achieved using low-hydrogen welding processes orelectrodes with appropriately high-heat input that slows thecooling rate. The use of low-hydrogen electrodes requiresthat special attention be given to electrode care and handlingrequirements. The cracking process is related to the hydro-gen absorbed by the hot weldment. A slow cooling rate is

API R~ PRACTw::e 1107

necessary to pennit diffusion and elimination of the hydro-

gen. Proper attention should be given to fit up and to the car-

bon equivalent factor and chemica1 composition of both the

sleeve and the carrier pipe.

beveled edges are to be smooth and unifonn with dimen-

sions conforming to the procedure specification.

4.4 Weather Conditions

Welding sball not be done when tbe quality of the corn-pleted weld would be impaired by the prevailing weatherconditions. Weather conditions d1at would cause impairmentinclude. but are not limited to. airbome moisture. blowingsands. and high winds. Wmdshields may be used when prac-tica1. The cornpany representative decides if weather condi-tions are suitable for welding.

4.2 Alignment

4.2.1 OFFSET ,

The offset between the abutting edges for groove weldsshould not exceed X6 inch (1.59 millimeters). To obtain thisalignment. devices .should be used. or misaligned surfacescan be built up with weld metal.

4.5 Clearance

When bell holes are used. they should be large enough toprovide the welder or welders widl ready access tO the work.

4.2.2 ROOT OPENING (COMPLETE

ENCIRCLEMENT RTTJNGS)

The root opening, d1e space between d1e abutting surfaces,

should be sufficient to pennit 100 percent penetration. Joints

paralleling the axis of the carrier pipe may be fitted with a

suitab1e tape or mild steel backup strip to prevent d1e we1d

metal fi'Om being fused to the surface of the carrier pipe.

4.6 Cleaning

Weld slag, scale. and spatter should be removed from each

weld bead and the adjacent base metal.

4.7 Welding Sequence

Suggested welding sequences for the welding of fittingsare shown in Figures 13 through 18.

4.3 Bevels

Edges oí tbe pieces 10 be joined may be beveled by a ma-chine tool or may be cut by 3D oxygen cutting process. The

~NOIe: 1bis is the suggested welding sequence; oth= may be followed at the discretion of the company.

PlpEUNE ~ WELDING PRACTa;s 15

~

~

¡¡:::'= ¡ ~

,~ ,

-~-- ~ ~

"

~ ~

~ ---' , . I ..

:1 '. 1

Note: This is d1e suggested welding seq\JeIk:e; odIers may be foUowed at tbe ~on oftbe company.

Figure 14-Reinforcing Saddle

ALTERNA11VEDESJGN

N~ This is Ihe suggesred welding seqIICIx:e: at Ihe discretion o! the compauy. ~ may be !o11owcd and cir-cumf=tial welds numbets 3 and 4 necd no1 be made.

~

API RECa.o.IENDED PRACT1CE 110716

~

NOIes:1. This is tbe suggested welding sequence: ~ may be followed al the disaetion oftbe company.2. Wben in operation. tbe fitting is al pipeline ~.

Rgure 16-Encirclement Tee

'~

ALTERNA1lVEDESIGN

~Note: This is lile suggested welding sequence; al the di~on of the company. others may be folJowed and cir-cumferential welds 3 and 4 need not be made.

PtPEUNE ~ WELDING PRACTICES 17

Nore: This is die suggestcd welding sequeuce; ~ may be fonowed at the ~ of die company.

Rgure 18-Encirclement SaddJe

SECTION 5-INSPECTION ANO TESTING OF MAINTENANCE WELOS

5.1 Right of Inspection

The company has the right to inspect all of the welds byvisual and nondestructive testing methods. The inspectionmay be made dwing and after the completion of the welding.The ~ of inspection shall be as specified by the com-

pany.

The nondestructive testing should be done in accordance

with Section 8 of API Standard 1104. The welds shall meet

the standards provided in Section 6 of this recommended

practice.

5.2 Visuallnspection

All welds shaII be visually inspected for geometric confor-

mance widl d¡e procedUIe specificaJ:ion and for conformanCe

widt Section 6.

5.4 Certification of Nondestructive

Testing Personnel

5.4.1 PROCEDURES FOR CERTIFYlNG

NONI)ESTRUCTIVE TESTING PERSONNEl-~~~,~;~~: :. ,.

For the te5t mediOd tObe ~ nondestructive testing per-

sonnel shall be certified in accordance with the recommen-

dations of ASNT SNT -TC-I A, and only Level II or Level m

personnel shall inteIpret the test results.5.3 Nondestructive Testing

The company should consider the size, the grade, the op-erating stress, the location of the piping, the fluid to be n-ans-~11ed in it, and the inherent limitations of the nondestructivetesting methods when detennining the degree of inspectionand the methods to be used. One or more nondestructive test-in2 methods mav be used in addition to vi~ual in~~tinn

5.4.2 RECORD OF CERTIFIED

NONDESTRUCTIVETESTINGPERSONNEL

A record of certified nondesb"uctive testing personnelshall be kent hv thP ~nrn~nv ~n"' thi~ rPI"nrri ~h~1I in~llInp

API ~ PRAcTa 110718

íails to comply with the requirements may be disqualified

from further work at the discretion oí the company.the results of the certification tests, d1e agency and person

granting the ceI1ification, and the date of certification. NOD-

desU1lctive testing personnel may need to be recertified if

there is any question about their ability. Also, a1 the option of

the company, they may need to be recertified at tbe begin-

ning of a project or consU1lction schedule. In any event, re-

certification sha],l be required a11east every 3 years.

Right of Rejection5.5

The company sha1l have the right to accept or reject any

weld that does not meet the requirements of the methods by

which it was inspected. The welder who makes a weld that

5.6 Qualification of Welding Inspectors

Welding inspec~ sha1l be qualified by their experiencewith and their training in the specific inspection tBSk theyperform. Their qua1ifications shall be acceptable to the com-pany. and documentation of d1ese qualifications shall be re-tained by the company and shall include. but not necessari1ybe limited to. d1e following:

a. Education and experience.b. Training.c. Results of any qua1ification examinarions.

SECTION6-STANDARDSOFACCEPTABIUTY:NONDESTRUCTIVETESTING

{INCLUDING VISUAL)

but may be elongated or irregular in shape like piping(wormhole) porosity. Surface porosity d1at occurs on anyweld pass and. in the opinion of d1e company, is excessiveshall be Iemoved before the dcposition of additional passes.When measuring the size of d1e radiographic indications thatporosity produces, d1e maximurn dimension of the indica-tions shal1 apply to this acceptance standaId.

6.1 Introduction

These standards of acceptability apply to the determina-tion of the s~ and type of defects l~ by visual and DOD-destructive testing. While circumferential and longitudina1butt welds sbaIl meet d1e standards of acceptability set forthin API Standani 1104. fi1Iet welds shall meet tbe standards ofacceptability set forth in this section.

6.4.1 Porosity shall be lmacxeplable wben any oí the íol-

lowing conditions exist6.2 Umitations of Test Methods

Since nondestructive testing metbods give limited indica-tion, the company may reject welds which appear to meet~ standards of a=prabi1ity if. in its opinion. d1e depth ofa discontinuity may be detrimental to the weld.

a. The size of an individua1 pore exceeds X incb (3.17 mil-

limeters).b. The size of an individual pore exceeds 25 perceDt of the

thinnest of tbe DOminal wa11 thicknesses joined.C. The distribution of scattered porosity exceeds tbe CODcen-

tt'arion pennitted by Figure 19 or 20.6.3 Incomplete Fusion

Incomplete fusion (1F) is defined as a discontinuity be-1 tween weld metal and base metal which is open to the exter-nal surface. Incomplete fusion shal1 be unacceptable whenany of the following conditions exist

a. The length of an individual indication of incornplete fu-

sion exceeds 1 inch (25.4 rnillimeters).b. The totallength of indicatiODS of incomplete fusion in anycontinuous 12-inch (304.8-millimeter) length of weld ex-

ceeds 1 inch (25.4 millimeters).c. The totallength of indications of incomp1ete fusion ex -

ceeds 8 percent of the weld length of any weld less than 12inches (304.8 mil1imeters) in length.

6.4.2 C1uster porosity (CP) occurring in any pass exceptthe finish pass sha11 comply with the requirements of 6.4.1.

Cluster porosity occurring in the finish pass sha11 be unac-

ceptable when any of the following conditions exist

a. The diameter of the cluster exceeds ~ inch ( 12. 7 millime-

ters). .b. The total accurnulated léi1gtbOf cluster porosity in anycontinuous 12-inch (304.8-millimeter) length of weld ex-

ceeds ~ inch (12.7 millimeters)..c. Any individual pore within a cluster exceeds X. inch (1.S9

millimeters ) in size.

Cracks6.56.4 Porosity

Porosity (P), including surface porosity, is caused by gas

b'aDDed by solidifvin~ weld metal. It is 2enerallv SDherical

PlPEI.»E MAINTENAta w~ PRACT1CES 19

Large

. .... .. .. .

2T

1 T...

~"

Nore: The sizc of die ps pockets is DOt drawn to scale; f(X" die JKOper ~ S« 6.4.1.

t.,;

Figure 19-Maximum Distribution of Gas Pockets: Wall Thicknesses

less Than or Equal to ~ (nch (12.7 Millimeters}

,",~

.~".'~

20 API ~ PRACTa 1107

~-

. .....

. . .. .

Large

. .. .

Medj~.

..

... .. . ..

~8 8

8 8

8 8.

..

..

...

AIigned (It1r8e « mae )

1: ." 4T-;.

8 8 8 .2T .8 8 8

I e e e-2T~

I 1T

Nace: 1be sizeofdle gas pockecs is DOt ckawn to scaie; for lile properdimensions, s= 6.4.1.

Rgure 2O-Maxjmum Distribution of Gas Pockets: Wall ThicknessesGreater Than ~ 1rd1 (12.7 Millimeters)

'-

p~ MAHTENAta WELDtNG PP.ACT1CES 21

weld metal contraction during solidification are not consid.ered injurious defects unless their length exceeds ~ inch(3.97 millimeters). With the exception of these shallowcnter cracks. no weld containing cracks. regardless of theirsize or location. shall be acceptable.

Table 4-Undercutting Umits

Depd1 ~gth

6.6 Undercutting

Undercutting is a groove melted into the base metal adja-

cent to the toe or root 9f a weld and left unfilled by weld

metal. Undercutting adjacent to the cover or root bead shall

DOt exceed the limits specified in Table 4.

Over X, inch (0.79 millimeter) (X Not ~eover 12X peICent of tbe pipe wa1l

dúckness.wbicbeverissmaller

Over Y.. inch (0.4 millimeter) 2 inches (SO.8 millimeters) in adIroIIgh X, inch (0.79 COIItinUOUS weId of 12 ÍI\clICSmillimeter) oc over 6 percent to (304.8 millimeters) (X X the12X percent of the pipe wa1l length of dIe weld; whichever isthickness. whicbever is smaller smaIIer

Y.. inch (0.4 millimeter) (X' 6 percent Acceptable. regard1ess of lengthof dIe .wall dúckness.plpe ,whichever is smaller

SECTION 7-REPAIR OR REMOVAL OF DEFECTS

7.1 Authorization for Repair by Welding

Defects may not be repaired without prior company au-thorization.

7.2 Removal and Preparation for

Repair of Defects

Before any repairs are made. the defects shall be entirely

rernoved to dte sound metal. and all slag and scale shall be

rernoved. When conditions requiJe it. prehearing should be

perfonned.

7.3 Testing of Repairs

Repaired areas sball be reinspected using the same

method that was previously used. Additional inspection

methods may also be used.

a. The crack is less than 8 ~nt of the weld length.

b. A complete repair procedure has been developed and

documented. The repair procedure shall include the follow-

ing:1. Method of exploration of the crack area.

2. Method of crack remova1.

3. PIeheat and interpass heat requiremenL

4. Welding procedm'e and type of e1ectrodesc.

5. Post-heat ~ent if req~

c. The repair is made under d¡e supervisi011 of a technician

experienced in repair welding techniques.

d. The weld is made by a qua1ified welder.

e. The newly prepared groove is examined by a magnetic

particle or liquid penetrant test to assure that the crack is

completely removed.

Other cracks are to be e1iminated by removing the section of

piping containing d1eIn.7.4 Procedure for Repair of Cracks

With the company 's authorization, cracks in or adjacent 10welds may be ~ if the following conditions exist:

'.

AckttIonaJ copies ~ from API PtbIicatIons and Disb"bJtIon:

(202) 682-8375

Information about API PIHlC8tions, Programa and ServK:es is

8V8I1abie 00 the Workf WIde Web at http://www.api.org

American

Peh"oleum

Institute

1220 L Street, Northwest

Washington, D.C. 20005-4070

202-682-8000