Leak resistant plug valve

Abstract

A plug-type gas valve in which a key with a radially extending passageway is supported to rotate between open and closed positions within a bore in a valve body, the passageway establishing communication between diametrically spaced inlet and outlet ports when the key is in its open position. O-rings are positioned in grooves formed in the outer surface of the key above and below the passageway and seal against the wall of the bore in the body to prevent leakage. To lubricate the O-rings and further guard against leakage, grease is injected into pairs of axially extending grease channels formed in the outer surface of the key. To prevent the grease from being blown out of the valve by high pressure when the valve is partially open, one grease channel of each pair communicates only with the upper O-ring groove while the other grease channel of each pair communicates only with the lower O-ring groove.

Dependencies are inferred from the claim text.