Swagelok check valves

Poppet and Lift Check Valves from Swagelok

Check valves are valves which are specifically designed to allow for the flow of liquid or gas in one direction while preventing backflow. There are many varieties of these valves, though the most common configurations are ball configurations and flap configuration.

Although the overall design is relatively simple, check valves are available in a variety of different, more specific designs, each best suited to different applications. Because a range of variables, including cracking pressure, maximum working pressure, and minimum and maximum temperature reseal pressure must be considered, deciding which type of valve is right for your unique application can be a challenge.

The Basics

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.

Though the opening and closing mechanisms of various valves differ, their basic operational functions are the same; valves open when cracking pressure is reached and close when pressure drops below the cracking pressure or when back pressure occurs.

Poppet and Lift Check Valves

At Swagelok, we specialize in two types of check valves — poppet valves and lift valves.

Poppet Check Valves

These are sometimes referred to as spring-and-poppet valves and they are a variation of ball check valves. As with ball check valves, the poppet of a poppet valve 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

These 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.

Working with Swagelok

With over 70 years of experience designing, developing, and manufacturing high-quality fluid system products, Swagelok is intimately familiar with the challenges involved in choosing valves for specific applications. To best serve our clients during this decision-making process, we’ve developed nine different 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 temperatures ranging from -50 degrees F to 400 degrees 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.

Learn More

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