Piping (internally and externally) shall be free of cutting burrs, loose scales, dirt, dust and other foreign matter before the installation.
Wherever possible, joints should not be placed beneath ground level in inaccessible places, confined places (for example cellars), air or ventilating ducts, space under flooring or lift shafts.
If joints have to be used in piping beneath ground level in inaccessible places or confined places, they shall be welded or brazed to minimize the risk of leakage which may lead to collection of hazardous gas.
Joints other than welded or brazed shall be readily accessible.
Piping shall be so located or protected so as to avoid extremes of temperature which might give rise to condensation or cracking of the gas.
Provision shall be made to avoid damage to the piping from its expansion, contraction and vibration and by settlement of the building by which it is carried.
Piping shall be protected against corrosive atmospheres and materials.
As far as possible, concealed piping shall be avoided. If concealed piping is used, it shall be protected against inadvertent damage, such as from nails and knocks, by its location, type of material used or sheathing.
Piping shall not be run in or through an air or ventilating duct, chimney, flue or lift shaft.
Piping up to an outside diameter of 12 mm shall be supported at intervals of about 50 cm by means of pipe saddles or clamps in a way to avoid sagging and shifting. For larger diameter pipes, suitable longer supporting intervals may be used.
It is recommended that if the pipes are run along a surface of a structure, the supports should be so designed that the joints are sufficiently clear of the surface to permit the use of tools without damage to the surface.
It is recommended that the piping passing through walls should be protected by a covering sleeve. If it is necessary to pack the space between the piping and the sleeve, a moisture-proof material which does not corrode the piping shall be used.
The distance between gas piping and electrical wiring system shall be at least 600 mm and, where necessary; they shall be securely fixed to prevent contact due to movement. The gas piping should run below the electrical wiring.
The distance between the gas piping and steam piping, if running parallel, shall be at least 150 mm. The gas piping should preferably run below the steam piping.
A main valve shall be fitted in the piping as near as possible to its point of entry into building with proper sealing arrangement.
It is recommended that the number of fittings used in an installation should be kept to a minimum in order to reduce the risk of gas leakage. As far as possible, straight lengths of piping should be used. Where there are bends in the pipeline, these should have a radius of at least five times the diameter of the pipe.
The open ends of piping and fittings (with the exception of terminal taps or valves in regular use) shall always be made gas-tight by means of either an appropriate terminal fitting or a plug, welded or brazed in position. Welding or brazing material shall have a melting point of at least 540°C.
The distribution pipeline in residential buildings shall always be laid on walls with proper cleat supports/hanged from the roofs with adequate clearance from wall surface so that surface preparation and painting will be easier. The piping shall be anchored to prevent undue strains on connected equipment and shall not be supported by other piping. The spacing of supports in gas piping installations shall not be greater than 1.8 m for 12 mm/15 mm dia pipe, 2.4 m for 20 mm/25mm dia pipe, 3 m for 40 mm dia pipe and above.
The pipeline connecting the storage shed to the main installation should preferably be brought overhead without creating any hazard for the people/vehicles passing through the same. In case of any foreseen hazard the pipeline can be laid underground in a trench filled up with sand of grading zone IV as per IS 383 having MS/RCC cover. The underground pipe shall be provided with adequate protection like wrapping coating, etc, for protection against corrosion.
The single stage pipeline network (down the range of first stage PRV) from the installation onward should work at pressure very close to the working pressure of the appliances. Under no circumstances, the pressure of the pipelines shall exceed 1.5 kg/cm2. This should be obtained by double stage regulation of pressure, if necessary.