Flo Control Spring Check Valve [1 1 2" Slip] [1 2 lb] (1011C15) borggeneral The FC 1963 and C 6900 compatibility The FC 1963 and C 6900 compatibility give this part practical value because cartridge filters work best when the replacement matches the intended housing and service application closely Front faceplate gaskets help maintain the seal at the exposed interface of the skimmer faceplate installation this spring check valve helps restore dependable one way flow control and contributes to better overall plumbing performance This type of part is especially useful when the surrounding plumbing remains serviceable and the issue is centered on valve wear or inconsistent internal movement