Volume-II of IV - GAIL

MECON LIMITED
REGD. OFF: RANCHI (BIHAR)
PROCESS & PIPING
DESIGN SECTION
NEW DELHI
STANDARD SPECIFICATION
TITLE Flushing and Testing SPECIFICATION NO. PAGE 4 OF 9
4.0 Testing
MEC/S/05/62/11 REVISION 0
Records in triplicate shall be prepared and submitted by the Contractor for each
piping system for the flushing done in the proforma in Exhibit F.
4.1 Extent of testing
With the exclusion of instrumentation. piping system fabricated or assembled in
the field shall be tested irrespective of whether or not they have been pressure
tested prior to site welding of fabrication.
To facilitate the testing of piping systems, vessels and other equipments may be
included in the system with the prior approval of Engineer-in-charge, if the test
pressure specified is equal to or less than that for the vessels and other
equipments.
Pumps, compressors and other votary equipments shall not be subjected to field
test pressures.
Lines which are directly open to atmosphere such as vents, drains, safety
valves, discharge need not be tested, but all joints shall be visually inspected
wherever necessary such lines shall be tested by continuous flow of fluid to
eliminate the possibility of blockage. However, such lines if provided with block
valve shall be pressure tested upto the first block valve.
Seats of all vales shall not be subjected to a pressure in excess of the maximum
cold welding pressure of the valve. Test pressure applied to vales shall not be
grater than the manufacturer is recommendation nor less than that required by
the applicable code. Where desirable set pressure is less than test pressure,
test shall be made through an open valve.
Instruments in the system to be tested, shall be excluded from the test by
isolation or removal, unless approved otherwise by the Engineer-in-charge.
Restrictions which interfere with filling, venting and drawing such as orifice plates
etc. shall not be installed unless testing is complete.
Control valves shall not be included in the test system. Where by-passes are
provided test shall be performed through the by-pass end/or necessary spool
shall be used in place of the control valve.