A valve assembly is disclosed for mounting through a wall having a first face and a second face defining a thickness there between. The valve assembly includes a valve body housing having an axially-extending inner bore. A valve body is telescopically received in the inner bore of the valve body housing, such that the valve body is axially movable with respect to the valve body housing. A valve is nested in a recess of the valve body. A locking element selectively engages the valve body housing and the valve body to lock a position of the valve body relative to the valve body housing.