Abstract: A double block and vent valve comprises a housing having an inlet and an outlet for introducing and discharging fluid to and from the valve and is defined at its ends by a first portion and an opposite second portion. The valve includes a flow directing throat disposed within the housing and interposed between the inlet and the outlet for communicating fluid therethrough and has a means for venting leached or trapped fluid externally of it. The flow directing throat has a flow discharging end portion associated with the housing first portion and has an opposite flow receiving end portion associated with the housing second portion. The flow receiving end portion and the discharging end portion of the flow directing throat are sized diametrically differently relative to one another such that fluid flow passing through the flow directing throat from the inlet to the outlet does so without substantially impeding its flow path.

Abstract: An improved combination steam and fuel oil supply and purge valve has a steam valve and actuator member which provides for a closed position, a purge operation with communication established between a steam supply line and a discharge line leading to an oil burner, and a burner operation position wherein the actuator portion of the member engages and opens a double-acting oil supply and recirculation valve member and thus establishes communication between an oil supply line and an oil discharge line to the burner. In its closed position the oil supply and recirculation valve member provides for communication between the oil supply line and a recirculation line which redirects oil to a storage tank or the like for reheating and for maintenance of a desired viscosity during burner shutdown.

Abstract: A steam and fuel oil supply and purge valve has a steam valve and actuator member which provides for a closed position, a purge operation with communication established between a steam supply line and a discharge line leading to an oil burner, a burner operation position wherein the actuator portion of the member engages and opens an oil supply valve member and thus establishes communication between an oil supply line and an oil discharge line to the burner. Oil recirculation is also provided together with a "cooling" steam feature. The latter is provided by the steam valve and actuator at an additional position where a metered flow of "cooling" steam is provided for inoperative burner tips when other burners remain in operation.

Abstract: A valve assembly for use in the passage of fluid in a conduit system wherein the valve assembly possesses an actuator part and a valve part for controlling the flow of fluid therein while simultaneously providing means for purging any residual fluid trapped within the valve assembly when the valve is in its closed position. The valve part of the valve assembly is made up of a cage means housing two flow-to-close valve members which are independently spring biased in the closed position. Placed within this cage member are venting means which provide a passage for trapped gases to escape through a vent duct system when the valve is in its closed position, but restricting the vent means when the valve is in its full open position.