Volume-II of IV - GAIL

MECON LIMITED
REGD. OFF : RANCHI (BIHAR)
Document6
PROCESS & PIPING
DESIGN SECTION
NEW DELHI
TITLE MAINLINE CONSTRUCTION
(ONSHORE)
STANDARD SPECIFICATION
SPECIFICATION NO. PAGE 35 OF 53
MEC/S/05/62/01 REVISION A
9.2.5 Moving supports, if any, shall be centered on their support and allow for a
movement of at least 300mm in both directions.
9.2.6 A comprehensive report/method statement on the laying operation to be used
shall be submitted to the COMPANY well in advance for approval. The report as
a minimum shall include, but not limited to the following:
(a) Method of installation by lifting (as a preferred method).
(b) Pulling method and related calculations, whenever lifting method cannot
be used.
(c) Pulling device and its characteristics
(d) Method of anchoring the pulling device
(e) Characteristics of the pulling rope
(f) Braking device, if any
(g) Pipeline assembly systems.
10.0 BACK-FILLING
10.1 Backfilling shall not be done until the pipe and appurtenances have the proper fit
and the pipe is following the ditch profile at the required depth that will provide
the required cover and has a bed which is free of extraneous material and which
allows the pipe to rest smoothly and evenly. Before any such work is done, it
shall be the CONTRACTOR's responsibility to first secure the approval of
COMPANY. If any backfilling is done without COMPANY's approval, COMPANY
will have the right to require removal of the backfill for examination, and the cost
of such uncovering and refilling shall be borne by CONTRACTOR. Backfilling of
trench in water courses shall be carried out as per the relevant specifications
issued for the purpose.
10.2 Backfilling shall be carried out immediately after the pipeline has been laid in the
trench, inspected and approved by the COMPANY, so as to provide a natural
anchorage for the pipeline, thus avoiding long exposure of coating to high
temperature, damaging actions of adverse weather conditions, sliding down
of trench sides and pipe movement in the trench. If immediate back filling is
not possible, a covering of atleast 200mm of earth, free of rock and hard lumps
shall be placed over and around the pipe and coating.