The standard specifies requirements for the installation, exchange, relocation and removal of credit or prepayment diaphragm and ultrasonic gas meters with a maximum capacity not exceeding 6 m3/h.
NOTE 1 For the purposes of this standard, installation includes design, inspection and commissioning. It is recognized that each of these tasks can be performed by the same person.
This part of BS 6400 is applicable to meter installations:
- supplied with 3rd family gases either:
- from low pressure service pipework with a maximum operating pressure not exceeding 75 mbar and a design maximum incidental pressure of 350 mbar; or
- from medium pressure service pipework with a maximum operating pressure exceeding 75 mbar but not exceeding 2 bar and a design maximum incidental pressure of 2.7 bar;
- only fitted downstream of the emergency control valve;
- that utilizes a meter regulator downstream of the emergency control valve;
- where all gas fittings subjected to medium pressure have been pre-assembled and where strength and gas tightness testing has been undertaken on the regulator assembly at the factory;
- where the operating pressure at the outlet of the meter is nominally 37 mbar.
Installation pipework is specified in BS 5482-1 and LPGA Code of Practice 25 [14].
Service pipework (including the first emergency control valve) is specified in BS 5482-1 and the LPGA Code of Practice 22 [15] and LPGA Code of Practice 25 [14].
This standard does not cover pressure regulating installations installed in a service pipework upstream of the emergency control valve.
NOTE 2 All pressures quoted in this standard are gauge pressures and all pressure absorption values are for liquefied petroleum gas unless otherwise specified.
NOTE 3 Additional guidance on domestic gas systems can be found in the European functional standards BS EN 1775.
NOTE 4 For additional guidance on the installation of gas meters in caravan holiday homes, residential park homes and permanently moored boats, reference should be made to IGE/UP/8 [16].