What is BS 6400-2 about?
BS 6400 discusses gas meters with a maximum capacity not exceeding 6 m3/h. BS 6400-2 specifies requirements for the installation, exchange, relocation, maintenance and removal of credit or prepayment or smart meters of the following types: diaphragm, ultrasonic and thermal mass gas meters with a maximum capacity not exceeding 6 m3/h.
BS 6400-2 is applicable to primary meter installations:
- Supplied with 2nd family gases from medium pressure gas distribution systems with a maximum operating pressure exceeding 75mbar but not exceeding 2 bar and with a design maximum incidental pressure of 2.7 bar
- Only fitted downstream of the emergency control valve
- That utilizes a pressure control and protection system contained within a regulator assembly that is 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 21 mbar, and installed external to the building
Note 1: For BS 6400-2, installation includes design, inspection and commissioning. It is recognized that each of these tasks can be performed by the same person
Note 2: For smart meters, this standard only covers the associated gas work
Note 3: Some legacy MP networks can operate at a design minimum pressure (DMP) of 35 mbar, 65 mbar, 105 mbar, 180 mbar and 270 mbar
Note 4: It is recognized that the final connection(s) to the gas service would not be subject to a strength test
Note 5: Installation, exchange, relocation, maintenance and removal of a secondary meter with a maximum capacity of 6 m3/h is specified in BS 6400-1
Who is BS 6400-2 for?
BS 6400-2 on the specifications for gas meters is useful for:
- Training establishments providing gas industry courses
- Consultants
- Architects
- Specifiers
- Meter and meter installation component manufacturers
- Housebuilders
Why should you use BS 6400-2?
A gas meter is a specialized flow meter, used to measure the volume of fuel gases such as natural gas and liquefied petroleum gas. BS 6400-2 guides you with aspects such as pressure control, regulator assembly, protection system, and low-pressure regulator. BS 6400-2 gives you guidelines for the location for meter installation, meter housing and proximity distance for meter and vent pipe tips.
BS 6400-2 provides pre-installation checks and safety precautions. BS 6400-2 guides you with the five-year inspection and maintenance plan for the gas meters.
BS 6400-2 helps you with the overall installation process and maintenance checks, which gives you reliable gas meter readings.
What’s changed since the last update?
BS 6400-2:2018 supersedes BS 6400-2:2006, which is withdrawn. BS 6400-2:2018 includes some technical changes with respect to BS 6400-2:2006. These include:
- Uses more up-to-date gas industry terminology
- Reflects changes in structure, practices, and product availability in the gas industry
- Provides additional information on the installation, exchange, relocation, maintenance and removal of gas meters with a maximum capacity not exceeding 6 m3/h supplied from medium pressure 2nd family gas networks
- Includes clauses on inspection and maintenance and risk assessment
- Covers meter installations of capacities not exceeding 6 m3/h in all locations (which now includes non-domestic)

