A plug valve assembly having an inlet and an outletcomprisesa housing including a bore extending through the housing between the inlet and the outlet and acavityintersecting the bore, a plug mounted in the cavity for rotation between first and second positions. In the first position an orifice extending through the plug is aligned axially with the bore of 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 are located in the cavitybetween the plug and an inner surface ofsaid cavityand a plug retaining member is releasably attachable to the housing. A surface of the plug retaining memberlimits upward movement ofthe plug in the housing. The housing includes a reinforcement collar extending around the inner surface of the cavity.