Abstract: A combination pressure-vacuum relief valve assembly is provided for mounting in a port of a container. A two-part, generally hollow valve housing defines a valve chamber and includes a housing body part adapted for mounting in the port and which has an inlet communicating with the container. A housing cap part is secured to the body part and defines an outlet therebetween. A pressure valve seat is formed on the housing body part surrounding the inlet. A two-part, generally hollow pressure valve is movably mounted within the valve chamber and includes a valve body part for engaging the pressure valve seat. The valve body part includes a first vacuum relief passage communicating with the container through the inlet. A valve cap part is secured to the valve body part and includes a second vacuum relief passage communicating with atmosphere through the outlet.
Abstract: Control apparatus for controlling the operation of a gas valve in a gas heating system which includes thermostatic switch means and a source of AC voltage which are connected to form a series circuit with the gas valve is disclosed. The control apparatus comprises switch means which is connected to provide continuity in the series circuit upon receipt of a first control signal and to remove the continuity in the series circuit upon removal of the first control signal. Isolation means receives a second control signal having a high state and an alternate low state and generates the first control signal when receiving the high state of the second control signal. A power supply receives the AC voltage when the thermostatic switch means is closed and provides a DC voltage to a timer means. The timer means then generates the second control signal.