Wafer-type swing check valve construction

DETAILED DESCRIPTION It is a feature of this invention to provide a wafer-type swing check valve construction that will not be adversely affected by the corrosive action of corrosive fluid and the like being passed through the valve construction.
In particular, it has been found according to the teachings of this invention that an improved wafer-type swing check valve construction can be formed of two simple parts, namely a metallic housing body and a metallic valve disc, with both parts being covered on all of the wettable areas thereof with a resilient corrosion resistant plastic material so that the housing body and the valve disc are completely protected from corrosive fluids and the like that might be passed through the valve construction.
Further, it has been found according to the teachings of this invention that since such plastic material is in the seating area of the valve construction, such plastic material will provide a tight seal between the valve disc and the valve seat of the valve body through a cold forming action of the plastic material as will be apparent hereinafter.
In addition, it has been found according to the teachings of this invention that since such plastic material covers the pivot pin-like part of the valve disc and the recess means of the housing body that loosely receives the pivot pin-like part to pivotally mount the valve disc in the housing body without requiring any holes to be formed in the housing body for such pivot arrangement that might adversely leak fluid, such plastic material will provide for corrosion free pivoting action of the valve disc as will be apparent hereinafter.
Also, it has been found according to the teachings of this invention that the matallic parts of the valve disc and valve seat can be so made that same will provide a metal to metal back-up closing of the valve seat should a fire or the like destroy the plastic material thereon in the valve seating area thereof and thereby effectively prevent further feeding of fluid through the valve construction to the fire as will be apparent hereinafter