11. In the case of a bus there shall be fitted as near as practicable to the gas container a valve which shall stop the flow of gas into the gas supply pipeline in the event of—
(a)the angle of tilt of the vehicle exceeding that indicated in regulation 4 of the Public Service Vehicles (Conditions of Fitness, Equipment and Use) Regulations (Northern Ireland) 1995(1), and
(b)the deceleration of the vehicle exceeding 5g.
S.R. 1995 No. 447, to which there are amendments not relevant to these Regulations