Abstract: A pressure regulator apparatus has a pressure regulator mechanism which includes first and second housing portions, each made of substantially rigid material, such as a PVC polymer, and each housing portion having a passageway therethrough. One of the housing portions has a plurality of niches formed therein while a second housing portion has a plurality of raised wedged members formed thereon so that the pressure regulator mechanism can be placed in the two housings which can be driven together to drive the housing wedge members of one portion of the housing into the niches of the other portion of the housing. Since both housings have a cylindrical portion, the wedge members are sized to extend above the inner lip of the other housing portion to thereby require a forced expansion of the substantially rigid housing portion to drive the wedge members into the locking niches in the other housing member which simultaneously locks the pressure regulator mechanism into position in the housing.