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 6 OF 53
MEC/S/05/62/01 REVISION A
3.1.1.4 DURING THUNDERSTORMS OR WHEN DISCHARGES ARE
OBSERVED ON INSULATORS ALL PERSONNEL MUST LEAVE THE AREA
OF THE HIGH VOLTAGE LINE AND PIPELINE.
3.1.1.5 To prevent electrical voltage in a non-buried section of the pipeline from
rising to dangerous levels, the length of the pipeline section which has been
welded together before burial must not exceed the length at which the max.
admissible voltage may be induced. This length may be calculated using an
approved calculation method.
3.1.1.6 Before a pipeline section is lowered into the trench the structure's earth
electrodes indicated in the drawings or determined with calculation method must
have been installed and connected both to the pipeline section already buried
and to the section which is about to be buried. The electrical connections which
serve the purpose of preventing dangerous voltages must have a min. area of
35mm 2.
Said connections must not be interrupted until after the permanent safety earth
connections have been installed and connected to the entire uninterrupted
pipeline.
3.1.1.7 The welded connection between the pipeline section and the section
already buried must be installed at a distance of at least 50m from the nearest
point of a pylon base.
3.1.1.8 Personnel doing work inside the area of influence of the high voltage
system must wear electrically insulating foot-wear (e.g. rubber kneeboots) and
wear insulating rubber or plastic gloves.
3.1.2 Additional measures for work at less than 50m from the centre of the high
voltage system.
If work is done at less than 50m from the centre of the high voltage system, the
regulations below must be complied with in addition to the rules specified in
clause 3.1.1.
3.1.2.1 The work must not be started until agreement has been reached with the
authorities which controls the high voltage system, about the implementation of
the safety measures specified in this section.