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 8 OF 9
MEC/S/05/62/11 REVISION 0
Prior to the start of any test or periodically during the field test programmes, all
test gauges shall be calibrated using a standard dead weight gauge tester or
other suitable approved testing apparatus. Any gauge having an incorrect zero
reading or error of more than ± 2% of full scale range shall be discarded. The
Engineer-in-charge shall check the accuracy of master pressure gauge used for
calibration.
4.4 Testing Pressure
4.4.1 Hydrostatic Test
All vents and other connections used as vents shall be kept open while filling the
line with test fluid for complete removal of air. For pressurising and
depressurising the system, temporary isolating valves shall be provided if valves,
vents, drains do not exist in the system.
Pressure shall be applied only after the system/line is ready and approved by
the Engineer-in-charge.
Pressure shall be applied by means of a suitable test pump or other pressure
source which shall be isolated from the system as the desired test pressure is
reached and stabilised in the system.
A pressure gauge shall be provided at the pump discharge for guiding the
system to the required pressure.
The pump shall be attended constantly during the test by an authorised person.
The pump shall be isolated from the system wherever the pump is to be left
unattended.
Test pressure shall be maintained for a sufficient length of time to permit
through inspection of all joints for leakage or signs of failure. Any joint found
leaking during a pressure test, shall be re-tested to the specified pressure after
repair. Test period shall be maintained for a minimum of three hours.
The pump and the piping system to be tested are to be provided with separate
pressure indicating test gauges. There gauges are to be checked by the
standard test gauge before each pressure test.