Volume-II of IV - GAIL

MECON LIMITED
REGD. OFF : RANCHI (BIHAR)
c:\fateh\standard\stad-eqp.wp
PROCESS & PIPING
DESIGN SECTION
NEW DELHI
STANDARD SPECIFICATION
TITLE Hydrostatic Testing of Onshore Cross- SPECIFICATION NO. PAGE 16 OF 17
country Pipelines
MEC/S/05/62/03 REVISION A
Where,
∆P = pressure change resulting from a temperature change (bar)
∆T algaebrical difference between water temperature at the beginning of the test
and water temperature as measured at the end of the test (°C).
B = value of the difference between the thermal expansion of water at the pressure
and temperature as measured at the end of the test and that of steel (°C -1 ) x 10 6
(Refer table – 1)
A = Isothermal compressibility value of water as estimated at the pressure and
temperature values obtained at the end of test (bar -1 ) x 10 6 (Refer Figure 1)
r i = nominal inner radius of the pipe (mm).
t = nominal thickness of pipe (mm).
13.0 PRECAUTIONS DURING THE TEST
In addition to all that has been expressly described in the procedures for carrying out
the tests, the following additional requirements shall be complied with:
13.1 Provision shall be made for the installation of no-admittance signs to unauthorized
personnel from the roads to the R.O.W.
13.2 Signs stating "PIPE UNDER TEST-KEEP OFF" with local language translation shall be
placed where the pipeline is uncovered, and particularly where the provisional traps
and stations are located. Such areas shall be suitably fenced in such a way as to
prevent access of unauthorized personnel. No unauthorized personnel shall be closer
than 40 m to the pipeline or equipment under test.
13.3 Provisional scraper traps shall be installed in compliance with methods and suitable
locations so that their rupture cannot cause any injuries to the personnel or third
parties.
13.4 The test station shall be placed in such a location as to prevent it from being affected
by a catastrophic failure in the test head.