Abstract: A valve actuating device is provided for opening and closing a valve of the type having a valve housing, a valve member sealingly engageable with a valve seat formed in the valve housing, and a valve stem attached to the valve member for moving the valve member between a closed position and an open position. The valve actuating device includes a housing which is attachable to the valve housing of the valve, a motor mounted on the housing, a pinion gear which is coupled to the motor by a shaft, the pinion gear being drivable by the motor via the shaft. The device further has a rack including a body having an end portion which is engageable with the valve stem of the valve and a longitudinal cutout along a side of the rack. The rack is moveable between a first position in which the valve is in its open position and a second position in which the end portion of the rack engages the valve stem for maintaining the valve stem in its closed position.

Abstract: A valve actuating device for opening and closing a valve is disclosed. The valve has a valve housing, a valve member sealingly engageable with a valve seat formed in the valve housing and a valve stem attached to the valve member for moving the valve member from an open position to a closed position, the valve member being biased to the open position. The valve actuating device includes a housing which is constructed to be attachable to the valve housing of the valve, a bidirectional motor mounted on the housing and a pinion gear which is coupled to the motor by a shaft, the pinion gear being drivable by the motor via the shaft.

Abstract: An automatic flow control valve for maintaining a predetermined output flow rate in response to a varying pressure differential across the valve has an orifice element, an occluding element and a spring each placed at least partially within a valve housing. The orifice element has a fluid port at a fixed and predetermined distance from an alignment end of the orifice element. The occluding element has an occluding region at a fixed and predetermined position relative to an alignment end of the occluding element. The spring extends along a longitudinal axis of the valve housing and the length of the spring in the absence of fluid flow is predetermined. In use, fluid flows longitudinally between the fluid port and the alignment end of the occluding element. This causes the alignment end of the orifice element to be aligned with one end of the compression spring and the alignment end of the occluding element to be aligned with a second end of the spring.