BS 3251:1976

This British Standard specifies requirements for hydrant, emergency water supply and meter bypass indicator plates made from sheet steel, cast iron, aluminium alloy or plastics materials, together with all removable characters and spacer pieces supplied with them.

Four types of plate are specified.

1. Class A plates: hydrant indicator plates for general use except on roads of motorway standard.
2. Class B plates: hydrant indicator plates for use on roads of motorway standard.
3. Class C plates: indicator plates for emergency water supplies, “EWS”.
4. Class D plates: indicator plates for meter bypass valves.

Dimensions for sheet steel, cast iron, aluminium alloy or plastics indicator plates. Colours and finish, tests for impact resistance, colour stability, resistance to weathering, flexibility and security of removable numerals. Recommendations for fixing.