Nozzle Type Check Valve | DFT Valves

Nozzle Check Valves

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There are innumerable fast-reversing fluid flow applications that require protection against surges or backflow, including axial flow scenarios.

DFT® has been a world-renowned manufacturer of in-line “non-slam” check valves since 1943. We offer a diverse line of reliable check valves, including a family of nozzle check valves that are an ideal backflow protection solution for virtually any application.

Nozzle Check Valve Basics

Nozzle check valves are specifically designed for applications where fluid, gas, or slurry is pumped at low pressure or with intermittent flow. They are designed to shut quickly and silently during low-pressure or no-flow periods, reliably preventing reverse flow.

In nozzle check valves, the closure mechanism involves a disc held against a seat by an internal spring. When the pressure of the fluid, gas, or slurry at the inlet exceeds the spring's closing force, the spring compresses, allowing fluxo pass freely. When the fluid flow slows or stops, the spring automatically closes the valve.

This unique design offers multiple advantages:

• Quick and dynamic responses to changes in flow pressure and velocity
• Minimized pressure loss
• Reduced or eliminated water hammer
• Elimination of valve chatter in low-flow conditions
• Protection for pumps and rotating equipment from reverse flows
• Zero leakage performance compared to other check valve types

Due to their unique characteristics, nozzle check valves are versatile and useful in various applications. They are critical for reducing water hammer in residential plumbing and for preventing backflow in heavy industrial applications such as chemical processing, cooling towers, and mine dewatering.

Nozzle check valves have proven particularly effective in chemical and petroleum processing plants. These valves effectively prevent backflow and provide tight shut-off performance in these settings. For processes requiring precise component percentages, such as ethanol-additive blending, backflow prevention is crucial.

DFT®’s Proprietary Nozzle Check Valves

Using state-of-the-art design and test simulation software, DFT® offers a broad range of nozzle check valve options. Our valves continually improve to be more efficient and reliable.

Our nozzle check valves feature several key differences from those of our competitors, both internally and externally:

• Body diameter — Our nozzle check valves have bodies larger than their inlets, resulting in superior flow characteristics.
• Disc design — Our disc faces are designed to maximize hydrodynamic efficiency and minimize pressure loss.
• Soft seat — All of our nozzle check valves feature a specially designed and sourced O-ring in the seat, drastically reducing reverse flow leakage and aiding in quiet valve closure.
• Single spring — We use a single spring designed for a million-cycle lifetime, unlike most companies that use multiple springs, minimizing potential failure points.

With more than 70 years of valve design and manufacturing experience, coupled with advanced design and testing software, DFT® produces five high-quality nozzle check valve models: Excalibur, WLC, ALC, PDC, and GLC.

If you want to learn more, please visit our website nozzle check valve manufacturers.

To learn more about our nozzle check valves and how to implement them in your system for maximum effect, contact us today.