3.01.OperatingProcedures.destructively Testing Welds

3.01 WELDING PROCEDURES MANUAL of 16

OPERATING PROCEDURES

DESTRUCTIVELY TESTING WELDS 12/31/06

HIS SECTION PROVIDES STANDARD PROCEDURES for destructively testing steel

welds. T GENERAL

Before being permitted to weld on the Company’s natural gas or propane piping, a welder must be qualified in accordance with Section 2.30 (“Qualifying Welders for Oxy-Acetylene Welding”), and/or Section 2.31 (“Qualifying Welders for Arc Welding]”) for in-active pipeline and appurtenances and/or Section 2.32 (“Qualifying Welders for Arc Welding for In-Service Welding]”) for welding on pipelines in-service. The quality of the welds performed in the qualification testing and in establishing a qualified welding procedure will be determined by destructive testing.

Sample test welds will be joined by following each detail of the Qualified Welding Procedure Specification (QWPS). The weld test specimens will be broken, pulled, or bent by an experienced person qualified to operate the test equipment. A representative of the individual overseeing welding activities or qualified external agency will examine and qualify test welds.

WELD COUPONS (TEST SPECIMENS): BUTT WELDS

See Table 3.01.1 for the minimum number of test specimens for the Procedure Qualification Test and the tests to which they must be subjected. The number of test specimens required for the Welder Qualification Test is outlined in Table 3.01.2.

TABLE 3.01.1: TYPE AND NUMBER OF TEST SPECIMENS FOR PROCEDURE QUALIFICATION TEST

OUTSIDE DIAMETER OF PIPE

NUMBER OF SPECIMENS

INCHES MILLIMETERS TENSILE STRENGTH

NICK-BREAK

ROOT BEND

FACE BEND SIDE BEND TOTAL

Wall Thickness < 0.500 Inch (12.7 Millimeters)

<2.375 <60.3 01 2 2 0 0 42

2.375-4.500 60.3-114.3 01 2 2 0 0 4

>4.500-12.750 <114.3-323.8 2 2 2 2 0 8

>12.750 <323.8 4 4 4 4 0 16

Wall Thickness > 1/2 Inch (12.7 Millimeters)

<4.500 <114.3 01 2 0 0 2 4

>4.500-12.750 >114.3-323.8 2 2 0 0 4 8

>12.750 >323.3 4 4 0 0 8 16

1

For materials with Specific Minimum Yield Strength (SMYS) more than 42,000 psi, at least one tensile test is required. 2 One nick-break and one root-bend specimen must be taken from each of two test welds, or for pipe less than 1.313 inches (33.4 mm)

in diameter, one full section tensile-strength specimen must be taken.




TABLE 3.01.2: TYPE AND NUMBER OF TEST SPECIMENS PER WELDER FOR WELDER QUALIFICATION TEST

OUTSIDE DIAMETER OF PIPE

NUMBER OF SPECIMENS

INCHES MILLIMETERS TENSILE STRENGTH

NICK-BREAK

ROOT BEND

FACE BEND SIDE BEND TOTAL

Wall Thickness < ch (12 ete 0.500 In .7 Millim rs)

<2.375 <60.3 0 0 43 0 2 2

2. 0 60 3 375-4.50 .3-114. 0 2 2 0 0 4

> < 4.500-12.750 114.3-323.8 2 2 2 0 0 6

>12.750 <323.8 4 4 2 2 0 12

Wall Thickness > 1/2 Inch (12.7 Millimeters)

<4.500 <114.3 0 2 4 0 2 0

>4. 50 >1 .8 500-12.7 14.3-323 2 2 0 0 2 6

>12.750 >323.3 4 4 0 0 4 12

3 One nick-break and one root-bend specimen shall be taken from each of two test welds, or for pipe less than 1.313 inches (33.4 mm)

in diameter, one full section tensile-strength specimen shall be taken.




Test specimens will be cut from the test welds at the locations indicated in Figure 1.

Figure 3.01.1

Note:1. At the company's option, the locations may be rotated, provided they are equally spaced around the pipe; however, specimens shall not include the longitudinal weld.

Nick-break

Face or side bend

Root or side bend

Top of pipe

Greater than 12 3/4" (323.8 mm)

Root bend or side bend

Face or side bend

Root bend or side bend

Face or side bend

Nick-breakTensile

Nick-breakTensile

Greater than or equal to 2 3/8" (60.3mm)but less than or equal to 4 1/2" (114.3mm)also, less than or equal to 4 1/2" (114.3mm)when wall thickness is greater than 1/2" (12.7mm)

Top of pipe

Nick-break

Root or side bend

Root or side bendNick-break

Root or side bend

Face or side bendNick-break

Tensile

Nick-breakRoot or side bend

Face or side bend

Tensile

See Note 2Nick-break

Greater than 4 1/2" (114.3 mm)

Face or side bend

Root or side bend

Nick-break

Tensile

Top of pipe

but less than or equal to

Tensile

12 3/4 (323.8 mm)

Top of pipeNick-break

Under 2 3 8" (60.3mm)




Weld reinforcementshould not be removedon either side of specimen

Approximatelly1" (25mm)

Wall thickness

Approximately9" (230 mm)

Figure 3.01.2

TENSILE-STRENGTH TEST

PREPARATION

Tensile test specimens will be approximately 9 inches long and approximately 1-inch wide as shown in Figure 3.01.2. If necessary, the specimens will be machined so the sides are smooth and parallel. They may be machine cut or oxygen cut. No other preparation is needed unless the sides are notched or are not parallel.

METHOD

The tensile-strength test specimen will be broken under tensile load, using equipment capable of measuring the load at which failure occurs. The tensile strength will be determined by dividing the maximum load at failure by the smallest cross-sectional area of the specimen, as measured before the load is applied:

Tensile Strength = PSI (load required to break) Cross Sectional Area of the coupon

REQUIREMENTS

The tensile strength of the weld, including the fusion zone of each specimen, must be greater than or equal to the specified minimum tensile strength of the pipe material, but need not be greater than or equal to the actual tensile strength.

NOTE: Pipe classification is normally referenced to its yield strength (see Table 3.01.3); welding rods are classified by tensile strengths (see Table 3.01.4).




TABLE 3.01.3: PIPE PROPERTIES

API PIPE GRADE MIN. YIELD STRENGTH

MAX. YIELD STRENGTH

MIN. TENSILE STRENGTH

MAX. TENSILE STRENGTH

B 35,000 65,000 60,000 110,000

X-42 42,000 72,000 60,000 110,.000

X-46 46,000 76,000 63,000 110,000

X-52 52,000 77,000 66,000 110,000

X-56 56,000 79,000 71,000 110,000

X-60 60,000 82,000 75,000 110,000

X-65 65,000 87,000 77,000 110,000

X-70 70,000 90,000 82,000 110,000

X-80 80,000 100,000 90,000 120,000

TABLE 3.01.4: ELECTRODE PROPERTIES

AWS CLASSIFICATION MIN. TENSILE STRENGTH

MIN. YIELD STRENGTH MIN. ELONGATION %

E6010 60,000 48,000 22

E7010G 70,000 57,000 22

E8010G 80,000 67,000 19

E9010G 90,000 77,000 17

E7018 70,000 57,000 25

E8018 80,000 67,000 19

E8018-C3 80,000 68-80,000 24

ER80S-D2 80,000 68-89,000 17-22.5

NOTE: The welder should be aware some procedures require specific pipe materials and electrodes be appropriately matched.

If the specimen breaks outside the weld and fusion zone (in the parent pipe material) and meets the minimum tensile-strength requirements of the specification, the weld will be accepted as meeting the requirements.

If the weld breaks below the specified minimum tensile strength of the pipe material, the weld will be set aside and a new test specimen prepared and subjected to tensile strength tests in accordance with this procedure.

If the specimen breaks in the weld or fusion zone and the observed strength is greater than or equal to the specified minimum tensile strength of the pipe material and meets





Approximately1" (25mm)

Wall thickness

Weld reinforcementshould not be removedon either side of specimen

Notch cut by hacksaw;specimen may be machine oroxygen cut; edges shall besmooth and parallel

3/4" (19 mm) min.

Approximately 1/8"(3.17mm)

Approximately 1/8"(3.17mm)

Figure 3.01.3

the soundness requirements of API 1104, the weld will be accepted as meeting the requirements.

If the break is in the weld zone and the observed strength of the weld is greater than or equal to the tensile strength of the pipe material and meets the

NIC

inches long and

certain

instead of the weld. When previous testing gh the pipe can be expected, the external

Nick-break specimens will be broken by pulling in a tensile machine, by supporting the ends and striking the center, or by supporting one end and striking the other end with a hammer. The exposed area of the fracture must be at least 3/4 inch wide.

requirements of the nick break test below, the weld is acceptable. The unit tensile strength in pounds per square inch may be derived by dividing the recorded maximum load by the original cross-sectional area adjacent to the weld. The tensile test may be omitted provided coupons designated for this test are subjected to the nick break test.

K-BREAK TEST

PREPARATION

Nick-break test specimens will be approximately 9approximately 1 inch wide as shown in Figure 3.01.3. The specimen may be machine- or oxygen-cut and should be dressed when the cuts are irregular or not parallel. They must be notched with a hacksaw on each side at the center of the weld, and each notch must be approximately 1/8 inch deep.

Nick-break test specimens prepared in this manner from welds of automatic and semiautomatic processes may fail through the pipeexperience indicates that failures throureinforcement may be notched to a depth of not more than 1/16 inch measured from the original weld surface (see Figure 3.01.4).

METHOD

Optional Nick TestSpecimen for Automatic andSemi-automatic Welding

Approximately 1/8" (3.17mm)

Transverse notch not to exceed 1/16" (1.59mm) in depth

3/4" (

19mm) min.

Figure 3.01.4




Maximum length of 1/32" (0.79mm)

1/2" (12.7mm) min Maximum length of 1/8" (3.17mm)or one-half wall thickness

Figure 3.01.5

Root-and Face-Bend Test Specimen: Wall Thickness less than or

Weld


Wall thickness


Specimen may bemachine or oxygen cut

equal to 1/2 Inch (12.7 Millimeters)

1/8" (3.17mm) max.radius all corners

Note: The weld reinforcement shall be removed from both faces flush with the surfaceof the specimen. The specimen shall not be flattened before testing.

Figure 3.01.6

ENTS

gas pockets must not nt of

RO

face-bend test specimens (see Figure 3.01.6)

hes long and approximately 1 inch

g edges must

REQUIREM

Exposed surfaces of each nick-break specimen must show complete penetration and fusion. The greatest dimension of any gas pocket must not exceed 1/16 inch, and the combined area of all

exceed two percethe exposed surface area. Slag inclusions must not be more than 1/32 inch in depth and must not be more than 1/8 inch or half the nominal wall thickness in length, whichever is smaller. There must be at least 1/2 inch of sound weld metal between adjacent slag inclusions. The dimensions should be measured as shown in Figure 3.01.5.

OT AND FACE-BEND TEST

PREPARATION

Root- and

will be approximately 9 inc

wide. Their lonbe rounded. They may be machine- or oxygen-cut. The cover and root-bead reinforcements will be removed flush with the surfaces of the specimen. These surfaces will be smooth, and any scratches that exist must be light and transverse to the weld.




METHOD

Figure 3.01.7

Root- and face-bend specimens will be bent in a guided jig similar to that shown in Figure 3.01.7. The radius of the plunger shall be 1.75 inch and the radius of the die shall be 2.9375 inches. The width of the die shall be 2.0 inches. Each specimen will be placed on the die with the weld at mid span. Face-bend specimens will be placed with the face of the weld toward the gap, and root-bend specimens placed with the root of the weld toward the gap. The plunger will be forced into the gap until the curvature of the specimen is approximately U-shaped.

REQUIREMENTS

The bend is acceptable if no crack or other defect exceeding 1/8 inch or one-half the nominal wall thickness (whichever is smaller), in any direction is present in the weld or between the weld and the fusion zone after bending. Cracks that originate on the outer radius of the bend along the edges of the specimen during testing, and which are less than 1/4 inch, measured in any direction, will not be considered unless obvious defects are observed.

SIDE-BEND TEST

PREPARATION

Side-bend test specimens (see Figure 3.01.8) will be approximately 9 inches long and approximately 1/2 inch wide, with their long edges rounded. They will be machine- or oxygen-cut to approximately 3/4 inch wide, then machined or ground to the 1/2-inch width. The sides will be smooth and parallel. The cover and root-bead reinforcements will be removed flush with the specimen surfaces.




See Note 1

Side-Bend Test Specimen: Wall Thicknesses Greater Than 1/2 Inch (12.7 Millimeters)


See Note 2

Wall thickness

1/8" (3.17mm) maximumradius on all corners

es flush with the surface of the specimen.

Wall thickness

1. The weld reinforcement shall be removed from both fac

2. Specimens may be machine cut to a width of 1/2 inch (1

3/4 inch (19 millimeters) and then machined or groun smooth and parallel

2.7 millmeters), or they may be oxygen cut to a width of approximately

d smooth to a width of 1/2 inch (12.7 millimeters). Cut surfaces shall be

Figure 3.01.8

S

d specimen will meet the same root- and face- bend test requirements described earlier.

TE

SamFigwill

At ared as shown in Figure 3.01.10. Specimens may be machine- or oxygen-cut. They should be at least 1 inch wide at the weld and long enough to be broken in the weld. For pipe less than 2-3/8 inches in diameter, it may be necessary to make two test welds to obtain the required number of test specimens. The specimens must be air cooled to ambient temperature before testing.

METHOD

Side-bend specimens will be bent in a guided bend test jig similar to that shown in Figure 3.01.7. Each specimen will be placed on the die with the weld at mid span and with the face of the weld perpendicular to the gap. The plunger will be forced into the gap until the curvature of the specimen is approximately U-shaped.

REQUIREMENT

Each side-ben

ST WELDS: FILLET WELDS (BRANCH CONNECTIONS)

ple test welds for fillet welded joints will be made to one of the configurations shown in ure 3.01.9, following all requirements of the procedure specification. Test specimens be cut from the joint at the locations shown in Figure 3.01.9.

least four specimens must be taken and prep




Note: This figure shows tgreater than or equal to 2

he location of test specimens for joints with a diameter 3/8 inches (60.3 millimeters). For joints with a diameter

e elds.

less than 2 1/8 inches (60.3 millimeters) specimens shall be cut from the samgeneral location, but two specimens shall be removed from each of two test w

METHOD/REQUIREMENTS

The fillet-weld nick break specimens will be broken in the weld by any convenient method. The exposed surfaces of each fillet-weld specimen must show complete penetration and fusion, and:

The greatest dimension of any gas pocket will not exceed 1/16 inch

The combined area of all gas pockets will not exceed 2 percent of the exposed surface area

Slag inclusions will not be more than 1/32 inch in depth nor more than 1/8 inch or one-half the nominal wall thickness in length, whichever is smaller

There must be at least 1/2 inch of sound metal between adjacent

ions inclus

The dimensions should be measured as shown in Figure 3.01.5.

Figure 3.01.9




3.01 WELDING PROCEDURES MANUAL Page 11 of 16



Figure 3.01.10

Approx.30°

bevel

Hacksawcut

Figure 3.01.10

Approx.30°

bevel

Hacksawcut

Flcu

amet

1"(25 mm)approx.

2" (50 mm)approx.

2" (50 mm)approx.

1"(25 mm)approx.

Flame cut

Approx.45°

Hacksaw cut


May be hacksaw notched




IN-SERVICE WELDING PROCEDURE QUALIFICATION

Before being permitted to weld on in-service Company natural gas or propane piping, the welder must be qualified in accordance with Section 2.32 (“Qualifying Welders for Arc Welding for In-Service Welding’). The quality of welds performed in the qualification testing and in establishing a qualified welding procedure will be determined by destructive testing. Sample test welds will be joined by following each detail of the Qualified Welding Procedure Specification. The weld test specimens shall be broken, pulled or bent by an experienced person trained and qualified to operate the test equipment. Examination and qualification of the typical destructive weld test specimens will be made by a representative of the Engineering Services department or qualified external agency as described above for tensile, nick-break, root bends, and side bends. Macro-etch test and Vickers hardness tests will be conducted by an external agency qualified in conducting these tests.

WELD COUPONS (TEST SPECIMENS)

See Table 3.01.5 for the minimum number of test specimens for the In-Service Procedure Qualification Test. The number of test specimens required for the Welder Qualification Test is shown in Table 3.01.6.

TABLE 3.01.5: TYPE AND NUMBER OF TEST SPECIMENS FOR PROCEDURE QUALIFICATION TEST

NUMBER OF SPECIMENS WELD TYPE

TENSILE STRENGTH

NICK-BREAK ROOT BEND FACE BEND SIDE BEND MACRO/ HARDNESS

TEST

TOTAL


GROOVE 2 2 2 2 0 0 8

SLEEVE 0 4 0 4 0 4 12

BRANCH 0 4 0 4 0 4 12

Wall Thickness > 0.500 Inch (12.7 Millimeters)

GROOVE 2 2 0 4 8 0

SLEEVE 0 4 0 4 0 4 12

BRANCH 0 4 0 4 0 4 12

Test specimens will be cut from the test welds at the locations indicated in Figure 3.01.11.




TABLE 3.01.6: TYPE AND NUMBER OF TEST SPECIMENS FOR WELDER QUALIFICATION TEST

NUMBER OF SPECIMENS WELD TYPE

TENSILE STRENGTH

NICK-BREAK ROOT BEND FACE BEND SIDE BEND MACRO/ HARDNESS

TEST

TOTAL


GROOVE 1 1 1 1 0 0 4

SLEEVE 0 4 0 0 0 0 4

Wall Thickness > 0.500 Inch (12.7 Millimeters)

GROOVE 1 1 0 0 2 0 4

SLEEVE 0 4 0 0 0 0 4




3.01 WELDING PROCEDURES MANUAL Page 14 of 16



Test specimens for root or face bends will have the branch or sleeve material removed and the weld ground flush with the carrier pipe material. These may be oxygen cut or machine cut, then machined to final thickness as shown in Figure 3.01.12. Specimens from the longitudinal welds will have the backing material ground off. The backing material used in welding the longitudinal welds will be .070 to .090 thick. The backing material is necessary to avoid penetration into the weld that would contact the carrier pipe. This penetration is undesirable since any crack that might develop is exposed to the hoop stress in the carrier pipe.

Figure 3.01.11




Since in-service welds that contact the carrier pipe are particularly susceptible to underbead or delayed hydrogen cracking, either ultrasonic, liquid penetrant or magnetic particle testing should be performed on the toe of the sleeve, saddle, and branch connections to the carrier pipe.

In addition, the welding sequence utilized for in-service welds is critical to avoiding the cooling sequences that could result in stress cracking. The sequence for sleeve welds should start with the longitudinal weld, then each circumferential weld. Each weld should be completely finished before beginning the next (e.g., both longitudinal welds should be completed before one end, and that end should be completed before the next).

Figure 3.01.12




wn in Figure 3.01.13.

These specimens should be machine cut oversized, then machined to 1/2” wide. The qualified agency will then smooth to appropriate tolerances and etch at least one face of each weld specimen with a suitable etchant to give clear definition to the weld structure.

A micro hardness test will be performed and the Vickers hardness measurement determined. Hardness measurements will be taken with three readings each:

Near the toe of the weld

Near the top of the weld

In the weld itself

In the heat-affected zone (HAZ) at appr

or additional information see Section 3.08: MACRO ETCH AND HARDNESS TESTING

Specimens to be prepared for macro-etch and Vickers Hardness tests should be prepared as sho

Figure 3.01.13

oximately one-half the wall thickness

If the Vickers hardness exceeds 320 for cellulose rods or 350 for low hydrogen processes, the specimen fails the test because the material is too hard for typical pipeline service conditions and could fail due to cracking depending on stresses encountered.

FOF WELDS.

3.01.OperatingProcedures.destructively Testing Welds

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