BS 1655:1950

Valves of conventional pneumatic-diaphragm-operated single or double beat type. Recommendation that applies to other types of automatic control valve for process control industry.

The following categories of flanged automatic control valves with metal bodies are covered in this British Standard.

Category 0.

1. Valves with flanges in accordance with BS 4504¹), PN 10 (10 bar) and PN 16 (16 bar).

   NOTE These face-to-face dimensions are subject to international negotiation; the listed dimensions may be used but are subject to agreement between the user and the manufacturer.

2. Valves with flanges in accordance with BS 1560²), Class 150.
3. Valves with flanges in accordance with Class 125 (see BS 5150³), Table 7).

Category 1.

1. Valves with flanges in accordance with BS 1560, Class 300.
2. Valves with flanges in accordance with BS 4504, PN 25 (25 bar) and PN 40 (40 bar).

   NOTE These face-to-face dimensions are subject to international negotiation; the listed dimensions may be used but are subject to agreement between the user and the manufacturer.

3. Valves with flanges in accordance with BS 10⁴), Tables up to and including Table J, also Table L, Table M and Table P.

   NOTE 1 Table C flange thicknesses are to be provided where valve flanges are called for in accordance with Table A and Table B, Table F thicknesses for Table D and Table F.

   NOTE 2 BS 10 is obsolescent.

Category 2.

1. Valves with flanges in accordance with BS 1560, Class 600.
2. Valves with flanges in accordance with BS 4504, PN 64 (64 bar) and PN 100 (100 bar).
3. Valves with flanges in accordance with BS 10, Table K and Table R.

   NOTE BS 10 is obsolescent.