Series CKS Check Valves are normally-closed in design. They feature a corrosion resistant PFA encapsulated spring which energizes a poppet seal that will neither stick nor chatter and is automatic in action.
Materials of Construction: Series CKS Check Valves are available standard in PVC (Polyvinyl Chloride), CPVC, Polypropylene and Kynar® PVDF in sizes 11/2", 2" and 3". Seals are in EPDM, or FKM. Threaded or socket connections are standard.
These 1/4" & 1/2" valves utilize a flexible elastomer disk as opposed to Plast-O-Matic's patented diaphragm. The advantage is that the CKD requires even less pressure than the CKM to open. The drawback, of course, is that it is dependent on some reverse pressure for sealing assistance, and in low flow applications requires gravity to seal (install with flow direction "up"). But please note that when used for liquids with a high specific gravity, the disk may "float," so it is therefore recommended to install with flow direction "down" with those types of liquids. Also note that in 1/2" piping systems where high flow is required, the 1/2" Series CKM check valve should be used, unless the super low cracking pressure of
Series CKD is absolutely a requirement. Flow performance of 1/4" size exceeds the recommended flow rates for fractional size tubing. • Very compact; slim design -- not much larger diameter than corresponding pipe size.