Abstract: A damping valve for a pressure regulator wherein the valve is actuated by a valve diaphragm and coacts with an inlet orifice formed in the transverse wall separating the inlet from the outlet. An outlet chamber is formed on the outlet side of the wall. A damping chamber is formed in the housing below the valve and separated from the outlet chamber by a flexible seal. A connecting rod passes through the central aperture in the seal, and has one end connected to the valve and the other end connected to a piston slidingly disposed in the damping chamber. The piston has a hexagonal head having six circular segmented openings or flats which provide passages for a hydraulic liquid which fills the damping chamber to pass from one side of the piston to the other whenever the piston is moved responsive to a corresponding movement of the valve.

Abstract: A slam-shut valve provides overpressure protection in a pipeline in the event of regulator failure. The slam-shut valve is normally held latched in the open position. Overpressure or failure of the regulator will automatically trigger operation of the slam-shut valve to close the same and prevent further passage of the gas through the pipeline. The slam-shut valve is manually reset to the open position once it has been triggered closed.The invention includes mounting the closing spring upon the lever in loaded position. The latch lever forms a subassembly, which in turn, is installed in the housing of the slam-shut valve to operatively interconnect the latch and release mechanisms and the reset mechanism. Subsequent to installing the lever, on end of the loaded closing spring is released from the lever to snap into position against the adjacent housing wall to bias the lever to the closed position. However, closing is normally prevented by the latch which releasably holds the lever in the open position.