BS EN 331:1998+A1:2010

1.1 This European Standard specifies the general requirements for the construction, performance and safety of ball valves and closed bottom taper plug valves. It also details the test methods and marking requirements.

It applies to metallic valves for domestic and commercial not directly buried installations inside or outside of buildings, using gases of the first, second and third family (specified in EN 437) and working up to 0,2 × 10 ⁵ Pa, 0,5 × 10 ⁵ Pa and 5 × 10 ⁵ Pa.

NOTE \'Not directly buried\' within the context of this standard means that valves below ground are not in direct contact with earth or other materials e.g. that they are in a protected encasement.

1.2 Valve nominal sizes (DN) covered by this European Standard are as follows: 6, 8, 10, 12, 15, 20, 25, 32, 40, 50.