(under subclass 39) Devices that are designed to simultaneously close the valves in branch pipes when the valve in the main gas supply is closed, also valve-locking means that will prevent the accidental opening of the valves.
SEE OR SEARCH THIS CLASS, SUBCLASS:
351, for automatic means on fluid fuel water heaters.
SEE OR SEARCH CLASS
70, Locks,
178, for valve encasing locks designed to prevent unauthorized operation of the encased valve.
431, Combustion,
153, for residual combustion apparatus having structure preventing the feeding of gaseous or liquid fuel when the apparatus is in a condition in which operation would be unsafe.
