Importance

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Abstract

A manually operated valve is usable as a shut-off and stop/check valve for handling refrigerant fluids in a system subject to reverse fluid flow. The valve comprises a hollow valve body having fluid inlet and outlet ports, a valve plate within the body with a fluid flow passage therethrough, an annular valve seat on the valve plate around the passage, a hollow internally threaded valve stem sleeve attached to the valve body, a rotatable and axially shiftable externally threaded valve stem extending through the valve stem sleeve into the valve body, and a valve disc which is rotatably and axially shiftably mounted on the inner end of the valve stem and releasably engageable with the valve seat to open and close the valve. Rotation and axial shifting of the valve stem effects axial shifting of the valve disc to open and close the valve to enable it to function as a shut-off valve. Axial shifting of the valve disc relative to the valve stem enables it to function as a check valve in reverse fluid flow conditions, when the valve stem is in a partially raised axial position. Rotation of the valve disc relative to the valve seat as they move into and out of engagement, which would eventually result in wear and leakage, is prevented by an anti-rotation pin which is mounted on the stationary valve sleeve and slidably engages a pin-receiving hole in the valve disc.

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First Claim