In general, offsites piping (except tankages area), electrical cable and instrumentation cable shall be laid either on pipe rack or on pipe sleepers.
Wherever piping is laid on pipe sleepers, hard surfacing/gravel is provided below it. Hard surfacing/gravel should be completed before start of pipe laying. Width of hard surfacing/gravel shall be about 1 meter more than the piping corridor on either side. This extra hard surfacing/gravel shall be for movement of operating personnel along the piping corridor. This movement area shall be approachable from the road at a distance of every 500 meters.
Overhead pipe bridges shall be used for pipes at road crossings. Culverts, if required, may be provided but to be minimised. Pipe bridges/culverts shall be adequately designed to take care of future requirements.
Clearance between Lines
Clearances between lines shall be minimum ‘C’ as given below. C=(do+Df)/2 + 25 mm + Insulation thickness(es) where, do – outside diameter of smaller pipe (mm) Df – outside diameter of flange(min 300#) of bigger pipe (mm). However this ‘C’ spacing between the offsite piping on the rack/sleeper can be suitably increased so that the lines should not touch each other after insulation/lateral expansion. Adequate clearance shall be provided for every long & high temperature lines to avoid clashing at the bends.
Expansion loops for all lines shall generally be kept at the same location.
Vents and Drains
Vents shall be provided on all high points & drains shall be provided at all low points. Drain valves at sleeper piping shall be kept outside the sleeperway if the same is not accessible and valves shall be put in horizontal only. At all such places where piping is extended to make drain valves accessible – 2 nos. of stiffeners, irrespective of pipe rating, shall be provided