A check valve assembly mounted on an end surface of a projection of a valve body. The check valve assembly includes a valve having a sealing surface on one side and a stem on an opposite side, and the valve body includes a fluid inlet intersecting the end surface of the projection. A rigid mounting plate has a first locating element adapted to locate the mounting plate with respect to the end surface on the projection. The mounting plate has a second locating element adapted to receive a fastener for attaching the mounting plate to the end surface of the projection. A clearance hole in the mounting plate is sized to receive the stem of the valve. The stem of the valve moves freely within the first clearance hole thus permitting the valve to move freely between open and closed positions.