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.

An independent vent to the outside of the building, sized in accordance with the manufacturers instructions/distributing company’s guidelines will be provided, where the location of a PRV is such that a ruptured diaphragm shall cause a hazard.

Where more than one PRV is installed, then each PRV shall have separate vent to the outside. The vent shall be designed to prevent the entry of water, insects, or other foreign material that could block the passage.

The height of the vent shall be 1.5 m above the eaves end of the shed or from the bottom of the roof. All vents connected to outlet of SRV, TRV etc., shall not be vented to the gas equipment flue or exhaust system should be obtained by double stage regulation of pressure, if necessary.

When multiple PRV are installed in a building/system, then they shall be marked by a metal tag or other permanent means indicating the building or part of the building/gas utilizing equipment being supplied.

Over pressure shut-off (OPSO) protection required to protect the downstream appliances from excessive pressure or the failure of the PRV shall be provided.

Under pressure shut-off (UPSO) protection shall be provided in PRV near gas utilizing appliances. This shall shut-off gas flow in case of low pressure in the downstream gas supply.