Patent ID: 8061687

Claim:
A plug valve having an inlet and an outlet, the valve comprising a housing including a bore extending through the housing between the inlet and the outlet, an upper section and a lower section respectively above and below a longitudinal centre axis of the bore, and a cavity intersecting the bore, a plug mounted in the cavity for rotation between first and second positions, wherein in the first position an orifice extending through the plug is aligned axially with said bore of the housing to allow fluid to flow from the inlet to the outlet and in the second position fluid is prevented from flowing from the inlet to the outlet, seals located in the cavity between the plug and an inner surface of said cavity and a plug retaining member releasably attachable to the housing, wherein a surface of the plug retaining member limits upward movement of the plug in the housing, and wherein the housing includes a reinforcement collar extending around the inner surface of the cavity in the upper section of the housing, said collar projecting inwardly into said cavity and defining an end surface thereon having a diameter less than a diameter of any other part of the inner surface of the cavity, and wherein the seals engage with an underside of the said collar.