Where the gas supply pressure is higher than that at which the appliance is designed to operate or varies beyond the design pressure limits of the appliance, a gas appliance pressure regulator shall be installed. (NFPA 54 9.1.18).
Clothes dryers, all automatically controlled space heaters, all domestic types of central heating furnaces, unit heaters, boilers, conversion burners, and floor or wall furnaces, whether operated by automatic or hand control shall be equipped with an appliance pressure regulator.
Connection of an appliance regulator to the gas supply line will be at a point downstream of the pilot line valve.
