This British Standard specifies the operational and health and safety requirements for underground fire hydrants conforming to the dimensional, material and performance requirements of BS EN 14339 and BS EN 1074-6. It also includes specific national requirements not included in BS EN 14339 and BS EN 1074-6. This British Standard applies to underground fire hydrants: a) to be installed in a water supply system; b) of size DN80; c) suitable for a maximum allowable operating pressure (PFA) of 1.6 MPa or 2.5 MPa; d) with operating valves; and e) with one outlet. It also specifies requirements for their surface box frames and covers.