14.—(1) No person shall install a primary meter or meter by pass used in connection with a primary meter unless—
(a)there is a regulator controlling the pressure of gas supplied through the meter or the by pass, as the case may be, which provides adequate automatic means for preventing the gas fittings connected to the downstream side of the regulator from being subjected to a pressure greater than that for which they were designed;
(b)where the normal pressure of the gas supply is 75 millibars or more at the inlet to the regulator, there are also adequate automatic means for preventing, in case the regulator should fail, those gas fittings from being subjected to such a greater pressure; and
(c)where the regulator contains a relief valve or liquid seal, such valve or seal is connected to a vent pipe of adequate size and so installed that it is capable of venting safely.
(2) Without prejudice to the requirements of paragraph (1), no person shall cause gas to be supplied from a gas storage vessel (other than a re-fillable cylinder or a cylinder or cartridge designed to be disposed of when empty) to any service pipework or gas fitting unless—
(a)there is a regulator installed which controls the nominal operating pressure of the gas;
(b)there is adequate automatic means for preventing the installation pipework and gas fittings downstream of the regulator from being subjected to a pressure different from that for which they were designed; and
(c)there is an adequate alternative automatic means for preventing the service pipework from being subjected to a greater pressure than that for which it was designed should the regulator referred to in sub-paragraph (a) above fail.
(3) No person shall cause gas to be supplied through an installation consisting of one or more re-fillable cylinders unless the supply of gas passes through a regulator which controls the nominal operating pressure of the gas.
(4) Without prejudice to paragraph (3) above, no person shall cause gas to be supplied through an installation consisting of four or more re-fillable cylinders connected to an automatic change-over device unless there is an adequate alternative means for preventing the installation pipework and any gas fitting downstream of the regulator from being subjected to a greater pressure than that for which it was designed should the regulator fail.
(5) Where a person installs a regulator for controlling the pressure of gas through a primary meter, a meter by pass used in connection with a primary meter or from a gas storage vessel, or installs a gas appliance itself fitted with a regulator for controlling the pressure of gas to that appliance, he shall immediately thereafter ensure, in either case, that the regulator is adequately sealed so as to prevent its setting from being interfered with without breaking of the seal.
(6) In relation to—
(a)gas from a distribution main, no person except the transporter or a person authorised to act on his behalf;
(b)gas from a gas storage vessel, no person except the supplier or a person authorised to act on his behalf,
shall break a seal applied under paragraph (5) above other than a seal applied to a regulator for controlling the pressure of gas to the appliance to which that regulator is fitted.
(7) A person who breaks a seal applied under paragraph (5) shall apply as soon as is practicable a new seal which is adequate to prevent the setting of the regulator from being interfered with without breaking such seal.