Volume-II of IV - GAIL

MECON LIMITED
REGD. OFF : RANCHI (BIHAR)
PROCESS & PIPING
DESIGN SECTION
NEW DELHI
\\Akjha\work contrac\standard TS for Pipe Line WC (Vol-II) MASTER FOLDER\04A major water crossing\Major Water Crossing -Final 04.doc
STANDARD SPECIFICATION
TITLE MAJOR WATER CROSSINGS SPECIFICATION NO. PAGE 9 OF 14
MEC/S/05/62/04 REVISION 0
After the temperature has been stabilised, the pressure shall be maintained in
the pipeline for at least twenty four hours and recorded by manothermograph.
During the test CONTRACTOR shall check all welds for leakage. Failure, if any,
during the test shall be rectified by the CONTRACTOR. If the same is due to
failure on account of any cause other than defect in material supplied by
COMPANY, the repairs shall be done free of cost, to the satisfaction of
COMPANY.
6.0 INSTALLATION
6.1 CONTRACTOR shall submit a detailed scheme for the method he proposes to
adopt for installing the pipeline to COMPANY for approval. CONTRACTOR shall
calculate all stresses in the pipeline while laying and check whether the stresses
remain within permissible limits. A set of all calculations shall be submitted to the
COMPANY for approval.
6.2 CONTRACTOR shall perform all work required to install the water crossings,
including the possible appurtenances indicated in the drawings. The water
crossings shall be installed in such a manner as to comply with the requirements
and conditions stated by the Authorities issuing the permits. CONTRACTOR
shall pay special attention to minimize any damage to embankments and dykes
in the vicinity of water crossings.
6.3 The equipment for launching shall be arranged in such a way that the pipeline is
laid without impact or jerking and is not subjected to stresses of any type other
than those which are allowable. Minimum allowed radius of curvature shall be
followed, particularly at the end of the launching way towards the water in the
freely suspended section.
6.4 After the water-crossing section has been installed in place, CONTRACTOR
shall fill this section including the pertaining land sections with water for the final
testing.
6.5 CONTRACTOR shall check if the position and depth of the water crossing are in
accordance with the approved drawings, by means of a profile of the pipeline,
before and after the water-crossing section is filled with water. CONTRACTOR
shall lower each pipeline section which is not sufficiently deep by dredging or
jetting the underlying ground.