GB528071A - - Google Patents

Abstract

528,071. Safety cut-off valves. FOWLER, L. J. April 26, 1939, No. 12554. [Class 135] A thermally operated valve adapted to control a main cut-off valve of the diaphragm actuated type for application to gas-fired boilers, water heaters, ovens and the like comprises a body or casing 10 mounted outside the combustion chamber and connected by a tube 18 to a block 19 mounted inside the combustion chamber. A bi-metallic strip 20 mounted on the block 19 is connected at its free end to a rod 17 adapted to open a spring- pressed valve 11 when heated by the flame of a pilot burner 24. The pilot burner 24 is supplied through pipe 23 connected to a pipe 27 through a duct 25 in the casing 10. The valve 11 controls a main gas cut-off valve 2, the arrangement being such that when the valve 11 is open gas leaks from the diaphragm chamber of the valve 2 through a pipe 4 and an inlet 13 so as to allow the main valve to open. The outlet 14 of the valve 11 is connected by a separate tube to an escape burner 15. Gas escaping from the control chamber of a main regulating valve 3 under the control of a thermostat 8 or a time switch is led by a pipe 9 to one of two connections on the body 10 whence it passes to the burner 15, the connection not used being suitably plugged. The strip 20 has a protective strip 22 of a corrosion resisting and heat resisting material.