A check valve, or non return valve, is a valve that prevents the fluid from flowing backwards and ensures that it flows in only one direction. It can be used to prevent the loss of prime of the pump and water hammer.

It is used in the food-processing, cosmetics, pharmaceutical and chemical industries as well as in the beverage, wine and oil production.

Operating principle

The check valve opens when the pressure of the fluid exceeds the pressure exerted by the spring. When the two pressures are compensated, the valve closes. A higher counterpressure will ensure the valve closes.

When there are two pumps operating alternately, the check valves are installed at the outlet of each pump to prevent the backflow when the pump is stopped. The obturation disc is provided with a perforation for a minimal circulation flow to avoid water stagnancy.

Design and features

Available sizes: DN 25/1″ to 100/4″.
Easy assembly/disassembly with the clamp.
Reduced size design.
Connections: Male DIN 11851.

Materials

Parts in contact with the product: AISI 316L (1.4404)
Other stainless steel parts: AISI 304 (1.4301)
Spring: AISI 302 (1.4319)
Gasket: EPDM according to FDA 177.2600
Internal surface finish: Ra ≤ 0,8 μm
External surface finish: Machined (turned)

Options

Gaskets: NBR, FPM or PTFE.
Connections: Weld DIN 11850, Weld OD ASME BPE, Clamp DN 32676, Clamp OD ASME BPE, Clamp, SMS, RJT, FIL-IDF, etc.
Perforation in the obturation disc.
ATEX version available.