Abstract: A compressor has an air inlet valve for controlling air intake when demand for service air from the compressor changes. The valve has a housing with an inlet and an outlet which is connected to a compressor. A rod in the housing is movable relative to the housing and has a shoulder and a piston. A movable valve member is mounted on the rod and a spring is interposed between the piston and the housing for moving the shoulder into engagement with the valve member and biasing the valve member toward the closed position. The housing has a chamber on each side of the piston for receiving air that discharges from the compressor. Air pressure is connected to one of the chambers to move the valve member toward the closed position when the pressure of air in the receiver tank exceeds a set-point.

Abstract: A start control for a compressor has an air inlet valve for reducing flow intake when a compressor is started. The valve has a housing with an inlet and an outlet which is connected to a compressor. A rod in the housing is movable relative to the housing and has a shoulder and a piston. A movable plate is mounted on the rod and a spring is interposed between the plate and the housing for biasing the plate toward a closed position in which the housing inlet is at least partially closed. A second spring is interposed between the piston and the housing for moving the shoulder into engagement with the plate and biasing the plate toward the closed position. The housing has a chamber on each side of the piston for receiving air that discharges from the compressor. Air pressure applied to one side of the piston assists the first spring and the second spring move the plate toward the closed position when the compressor is in a start mode of operation.