Abstract: An orifice installation for centering the center of a plate carrying device within a fitting is disclosed. The plate carrying device has a centering opening at its base which interacts with a stop pin in the base of the fitting. The plate carrying device further has ears on either side which interact with ears formed on the sides of an enlarged opening in the fitting to receive the carrying device therein in order to laterally center the carrying device. An opening is also formed in the top of the carrying device in which a plunger pin is positioned. A valve carrier of the fitting has a downwardly facing extension which upon positioning of the plate carrying device within the enlarged opening in the fitting and moving the valve carrier into place will contact the plunger pin, further stabilizing the carrier device within the fitting.