is in its closed position the ring portion is preferably formed of metal the valve member further includes a smoothly tapered leading edge 56 to smooth flow of fluid past the valve member in this embodiment the second portion 37 of the housing shown in detail in fig2 a which functions to retain the spring housing also functions as a clip which is press fit into the eye to secure the valve subassembly in place in the eye the second portion is preferably formed of resilient material e g spring steel so that it can be easily snapped in and out of the eye spring housing 44 and spring housing cap 46 and valve member are preferably soft brass the housing and valve clip are preferably formed of spring steel e g 304 stainless steel 30 gauge fig3 shows the valve subassembly of fig2 installed in a hydronic circulator the valve is shown in its closed position but would be moved to the open condition by flow in the direction of the arrows the valve subassembly could be easily removed and replaced simply by removing pump 10 and snapping the valve subassembly out of the eye fig4 5 show alternate check valve constructions for clarity these constructions are not shown provided in a valve subassembly housing however it is preferred in most cases that the valve be provided in the form of a valve subassembly for ease of installation and.