What is BS 746 - Gas meter unions and adaptors about?

A gas meter is a specialised flow meter, used to measure the volume of fuel gases such as natural gas and liquefied petroleum gas. Gas meters are used in residential, commercial, and industrial buildings that consume fuel gas supplied by a gas utility.

BS 746 discusses standards for gas meter unions and adaptors. BS 746 specifies requirements and test methods for unions and adaptors for the installation of low-pressure gas meters. BS 746 is applicable to unions and adaptors for gas meters for use with 1st, 2nd and 3rd family gases at temperatures between –20 °C and +60 °C, up to a maximum operating pressure of 75 mbar and a maximum incidental pressure of 200 mbar. The gas tightness of the gas meter unions and adaptors is also specified.

BS 746 also provides terms and definitions related to gas meter accessories. BS 746 specifies fittings to be used in conjunction with gas meters such as those specified by BS EN 1359 and BS EN 14236.

Who is BS 746 - Gas meter unions and adaptors for?

BS 746 on gas meter unions and adaptors is useful for:

The gas meters industry
Manufacturers and suppliers of gas meter unions and adaptors
Organisations that design and maintain gas meter adaptors and unions
Research and development team
Quality control personnel
Inspection bodies

Why should you use BS 746 - Gas meter unions and adaptors?

Gas Meter Unions are used for fitting onto a meter bracket. Gas meter unions and adaptors connect a gas meter to piping and allow it to rotate with increased movement by providing 360 degrees of motion. This ultimately reduces stress on the gas connector which prolongs the service life and sustains a safe, secure connection.

BS 746 provides you with all the requirements and specifications such as boss dimensions, nut dimensions, liner dimensions, increasing adaptor dimensions, union washer dimensions, adaptor washer dimensions, sealing disc dimensions, external thread dimensions, internal thread dimensions.

Following guidelines provided in BS 746, help you to ensure the quality and functionality of gas meter unions and adaptors, this helps to keep your gas meter accessible and safe.

What’s changed since the last update?

BS 746:2014 supersedes BS 746:2005+A1:2009, which is withdrawn. BS 746:2014 includes some principal changes with respect to BS 746:2005+A1:2009. These include:

Dimensional changes have been made to ensure that the flat parts of the nuts engage directly on the flat parts of the liners such that even pressure is applied to the surfaces of the washers
The properties of the sealing washer have been redefined
Additional tests for fittings and washer performance have been added
Hexagonal nuts are now permitted as an alternative to octagonal nuts

BS 746:2014

Specification for gas meter unions and adaptors

Current

Published:

30 Nov 2014