Volume-II - GAIL

6.2.7.3
(New)
6.2.7.4
(New)
Procedure
X-65 : 0.1100
X-70 : 0.1075
The Mandrel shall be plunged into the specimen, with the weld in contact with the mandrel, to
such a depth that the angle of engagement between mandrel and specimen reaches 60 0
(Refer Fig. 6.2.7 of this specification). If the combination of diameter and wall thickness of
pipe, and radius of mandrel is such that the angle of engagement does not reach 60 0 the
mandrel shall be plunged into the specimen until opposite walls of the specimen meet.
Acceptance Criteria
A specimen which fractures completely prior to the specified engagement of mandrel and
specimen, or which reveals cracks or ruptures in the weld or heat affected zone (HAZ) longer
than 4mm, shall be rejected. Cracks less than 6mm long at the edges of the specimen shall not
be cause for rejection. Dye penetrant testing may be used to positively confirm cracks or
openings.
7.0 DIMENSIONS, WEIGHTS, LENGTHS, DEFECTS, AND END FINISHES
7.1 Measuring equipment for inspection and testing shall be selected such that it has a resolution
and accuracy at least five times (5 X) finer than tolerance of the parameter being measured.
Similarly, standards against which a piece of equipment is caliberated shall be at least five
times as accurate as the equipment being calibrated.
7.2 Diameter
Only measuring equipments which can be demonstrated to have previously calibrated
satisfactorily and still be within its documented calibration period (interval) shall be used for
inspection and testing.
Note : These requirements apply to all inspections and tests performed to verify compliance
with this specification (not only dimensions and weights).
Pipe Body
The outside diameter of pipe body (for welded pipes), as determined by taping the
circumference, shall not deviate by more than the value given in Table E - 6B and E-6C
Appendix E. API Spec. 5L Table-7 stands modified accordingly.
Pipe Size Tolerance
≥ 4½” and < 20” : ± 0.75% of specified OD or ± 3 mm whichever is smaller
≥ 20” and ≤ 36” : + 3 mm, -0.25% of specified OD
> 36 : ± 3mm
Pipes Ends
Diameter tolerances for the pipe ends indicated in API Spec. 5L Table-8 shall be applicable on
the inside diameter for pipe sizes ≥ 14” and on outside diameter for pipe sizes ≤ 12”.
The specified inside diameter, based on circumferential measurement, over a length of 100
mm from the end shall comply with the tolerances specified in API Spec. 5L. Specified inside
diameter is defined as ID = ( OD - 2WT) where ID, OD & WT are the specified inside diameter,
specified outside diameter and specified wall thickness respectively.
GAIL (INDIA) LIMITED CARBON STEEL LINE PIPES GAIL-TS-LINEPIPE-CS
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