Swagelok SS-4C-1 — poppet check valve with a 316 stainless steel body and 1/4 in. Swagelok tube fitting end connections, factory-set cracking pressure 1 psig (0.07 bar). Part of the Swagelok instrumentation valve program for gas and liquid service on instrument, sample and small-bore tubing lines. Maximum working pressure and temperature ratings are governed by the valve series, seat/packing material and mounting per Swagelok catalog MS-01-176; select and install against the applicable Swagelok data sheet.