Swagelok specializes in two types of check valves: poppet valves and lift valves. In fact, we offer nine series of poppet and lift valves. Our primary poppet valve lines—the C, CA, CH, CP, and CPA series—can withstand working pressures as high as 6,000 psig and temps ranging from -50 F to 400 F. Cracking pressures range from 1/3 to 600 psi, flow coefficients range from 0.10 to 4.7, and size ranges from 0.125 in. to 1 in. Our other lines include the IPT-series, the 50-series, the CHP-series UHP valves, and CW-series, an all-welded, high-purity line.
Scroll down to learn more about the poppet check valves and lift check valves available. Fill the form on this page to access all Swagelok check valve catalogs.
Also referred to as clack valves, non-return valves, or one-way valves, check valves are a type of one-way valve with two ports. Fluid enters the valve via one port and exits, moving in the same direction, from the second port. These valves are often used for fluid mixing, as they’re able to prevent mixed fluids from flowing back to a pre-mix stage.
These are sometimes referred to as spring-and-poppet valves and they are a variation of ball check valves. The poppet is held in place by a spring. When the cracking pressure of a poppet valve is reached, the spring compresses, pushing the poppet back from an O-ring located at the inlet and the allowing fluid to pass straight through the valve.
Lift check valves are simply a variation of a poppet valve. Instead of having a fully linear flow, the fluid is redirected into a chamber perpendicular to the main flow. The chamber is sealed by a poppet, which is closed by gravity rather than the force of a spring. Lift valves are best suited to applications that do not require complete cessation of flow.
These lift check valves limit reverse flow under pressures up to 6000 psig (413 bar) and temperatures up to 900°F (482°C). Forward flow lifts the poppet, opening the valve. Reverse flow seats the poppet against the orifice, closing the valve. The lift check valve is gravity assisted and must be mounted horizontally, with bonnet nut on top.
The all-welded design of our CW Series valves provides reliable containment of system fluid. Forward flow starts at less than 2 psig (0.14 bar) pressure differential. The valve closes with less than 2 psig (0.14 bar) back pressure. 316L SS body offers enhanced material purity. Choice of standard or high-purity wetted surface finishes.
Every C, CA, CH, CP, and CPA series check valve is factory tested for crack and reseal performance with a liquid leak detector. Check valves with adjustable cracking pressures, CA and CPA series, are tested at two pressure points. Every valve is tested at a low-pressure setting and at a high-pressure setting. Valves must seal in 5 seconds at appropriate reseal pressure.
Fluorocarbon FKM O-rings are standard in 316 stainless steel valves; Buna N O-rings are standard in brass valves. Other elastomer seals (poppet bonding material and O-ring) are available. Springs of alloy 400 or alloy C-276 are available in some sizes. Valve bodies of alloy 400, carbon steel, aluminum, or other alloys are available in some sizes.
All kits include instructions. C, CP, CA, CPA Series Seal Kits contain O-ring; Spring Kits contain spring and two cracking pressure labels. CH Series Seal Kits contain bonded poppet, body seal O-ring, PTFE backup ring; Spring Kits contain spring and two cracking pressure labels. CA, C Series Metal Gasket Kits contain PTFE-coated gaskets. Other kits are available.