Volume-II of IV - GAIL

MECON LIMITED
REGD. OFF : RANCHI (BIHAR)
PROCESS & PIPING
DESIGN SECTION
NEW DELHI
STANDARD SPECIFICATION
TITLE WELDING OF ONSHORE GAS
SPECIFICATION NO. PAGE 17 OF 48
PIPELINES
MEC/S/05/62/02 REVISION
Any weld which as a result of radiographic and/ or ultrasonic examination in the
opinion of COMPANY exhibits imperfections greater than the limits stated in API-
1104 latest edition or as superseded in this article shall be considered defective
and shall so be marked with an identification paint marker.
In addition to the API-1104 requirements, the welds containing cracks including
crater cracks regardless of size of location is unacceptable.
1. Any length of inadequate penetration of the root bead as defined by API-
1104 is not acceptable except that root concavity is allowed as per API
1104.
2. Any amount of incomplete fusion at the root of the joint as detailed in API
1104 is considered unacceptable.
3. Unrepaired burn through areas are unacceptable.
Suitable records shall be maintained by the CONTRACTOR as desired by the
COMPANY on the day to day work done on welding, radiography, ultrasonic
testing. The CONTRACTOR shall present the records to the COMPANY on day
to day basis and whenever demanded, for approval.
12.6 Destructive Testing
The COMPANY has the authority to order the cutting of upto 0.1% of the total
number of welds completed for destructive testing at no extra cost of COMPANY.
The destructive testing of weld joints shall be made as per Clause 14.0.
In addition, welds already cut out for defects for any reason may also be
subjected to destructive testing. The sampling and the re-execution of welds shall
be carried out by the CONTRACTOR at his own expense. If the results are
unsatisfactory, welding operations shall be suspended and may not be restarted
until the causes have been identified and the CONTRACTOR has adopted
measures which guarantee acceptable results. If it is necessary in the
COMPANY's opinion the procedure shall be re-qualified. The weld joint
represented by unsatisfactory welds shall stand rejected unless investigation
prove otherwise.
13.0 REPAIR OF WELDS
13.1 With the prior permission of COMPANY, welds which do not comply with the
standards of acceptability shall be repaired or the joint cut out and re-welded.
\\Akjha\work contrac\standard TS for Pipe Line WC (Vol-II) MASTER FOLDER\02A welding onshore gas pipeline\Welding of Onshore Gas Pipelines with addendum - I 02A.doc