What is the difference between non-return check valves and resilient hinge check valves?

What exactly is a non-return valve? Why are they sometimes referred to as swing check valves? Where does a Resilient hinge check valve fit in?

The terminology surrounding swing check valves can be confusing. With so many different names for essentially the same product; a valve specifically designed to prevent back-flow in water and wastewater applications, it seemed sensible to produce a short blog post explaining the difference between these valve types.

Non-Return valves for water applications

Non-Return Valves, NRV’s, Reflux Valves and Check Valves all have a common functionality but are known by a variety of terminology.

A Non-Return Valve is specifically designed to prevent the back flow or reverse flow of a liquid or gaseous media and to protect the pump from the damaging surge pressures of water hammer following pump shut-down.

Different types of Non-return valves

These valves come in various forms including;

• Swing check valves (with options for springs, weight, levers and guards)
• Flap check valves
• Duckbill check valves
• Dual Disc check valves
• Tilted Disc check valves
• Silent check valves
• Nozzle check valves
• Ball check valves
• And now - Resilient Hinge Check Valves.

Resilient hinge check valves

The valve type ‘Resilient Hinge Check Valve ‘ is a new addition within WIMES and is described as;

A combined hinge and disc of moulded elastomer, steel reinforced but fully encapsulated with integral drop-tight O-ring, 45° seat and 35° stroke.

It operates faster than a Ball or Swing Check with or without the facility to speed up closure and was originally designed to work clog-free in the vertical.

With the only moving part guaranteed for 25 years, the Resilient Hinge Check Valve is ideal for‘fit and forget’ applications within a typical Sewage Pumping Station or handling sludge in a Treatment Works.