The Road Vehicles (Construction and Use) Regulations 1986

2.—(1) Every gas container shall—

(a) be capable of withstanding the pressure of the gas which may be stored in the container at the highest temperature which the gas is likely to reach,

(b) if fitted inside the vehicle be so arranged as to prevent so far as is practicable the possibility of gas entering the engine, passenger or living compartments due to leaks or venting from the container or valves, connections and gauges immediately adjacent to it, and the space containing these components shall be so ventilated and drained as to prevent the accumulation of gas,

(c) be securely attached to the vehicle in such a manner as not to be liable to displacement or damage due to vibration or other cause, and

(d) be so placed and so insulated or shielded as not to suffer any adverse effect from the heat of the exhaust system of any engine or any other source of heat.

(2) Every portable gas container shall be either—

(a) hermetically sealed, or

(b) fitted with a valve or cock to enable the flow of gas from the container to be stopped.

(3) Every fixed gas container shall—

(a) be fitted with—

(i) at least one pressure relief valve, and

(ii) at least one manually operated valve which may be extended by an internal dip tube inside the gas container so as to indicate when the container has been filled to the level corresponding to the filling ratio specified in the British Standards Institution Specification for Filling Ratios and Developed Pressure for Liquefiable and Permanent Gases (as defined, respectively, in paragraphs 3.2 and 3.5 of the said Specification) published in May 1976 under the number BS 5355, and

(b) be conspicuously and permanently marked with its design pressure.

(4) If any fixed gas container is required to be fitted in a particular attitude or location, or if any device referred to in sub-paragraph (3) above requires the container to be fitted in such a manner, then it shall be conspicuously and permanently marked to indicate that requirement.

(5) If the operation of any pressure relief valve or other device referred to in sub-paragraph (3) above may cause gas to be released from the gas container, an outlet shall be provided to lead such gas to the outside of the vehicle so as not to suffer any adverse effect from the heat of the exhaust system of any engine or any other source of heat, and that outlet from the pressure relief valve shall not be fitted with any other valve or cock.