Volume-II of IV - GAIL

MECON LIMITED
REGD. OFF : RANCHI (BIHAR)
PROCESS & PIPING
DESIGN SECTION
NEW DELHI
STANDARD SPECIFICATION
TITLE Hydrostatic Testing of Onshore Cross- SPECIFICATION NO. PAGE 4 OF 17
country Pipelines
MEC/S/05/62/03 REVISION A
e) Procedures for levelling and stabilization after filling and for pressurization and to
allow for temperature stabilization.
f) Pressure testing procedure including a complete description of all proposed
equipment and instruments (including spares), their location and set-up, and
proposed system for observation and recording of data during the pressure test.
g) Procedure for detection and location of leaks.
h) Procedure for dewatering the pipeline section(s) after testing, including a
complete description of all proposed equipment and instruments, (including
spares), their location and set-up, the type and sequence of pigs and the pig
tracking system along with the pig specifications.
i) Forms for recording the test data.
5.0 TEST DURATION AND PRESSURE
5.1 The duration of hydrostatic test shall be a minimum of 24 hours after stabilization and
the test pressure shall be as indicated in the approved hydrostatic test diagram.
5.2 Unless specified otherwise in the CONTRACT, the maximum base pressure shall not
be higher than the one resulting in a hoop stress corresponding to 90% of SMYS of
pipe material based on the minimum wall thickness in the test section and minimum
test pressure shall not be lower than the one resulting in a hoop stress corresponding
to 85% of SMYS of pipe material based on the minimum wall thickness in the test
section.
6.0 EQUIPMENT AND INSTRUMENTATION
The CONTRACTOR shall furnish all necessary equipment for performing the work as
stated in cleaning, flushing, filling, levelling, stabilizing, testing and dewatering
procedures. This shall include the following :
a) Pigs for filling , cleaning and gauging including
- Cleaning pigs with spring loaded steel wire brushes except for internal coated
pipes. In this case pigs to be provided with nylon / polyurethane brushes.
- Four cup batching pigs
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