Non Return Valves

Preventing back-filling sewage pipes

Property flooding can also occur from the back-filling of sewerage pipes, causing flood water to enter via downstairs toilets and showers, plug holes, dishwashers, washing machines etc.

The traditional solution to this problem has been to excavate a new manhole chamber outside the property and fit non-return valves to the existing pipes to eliminate the possibility of backflow. This can be expensive and time consuming.


Universal Fit Water and Rodent (WAR) Valve

The WAR Non Return Valve is easy to fit and operates on 110mm/4″ straight or bent** inspection chamber pipes constructed from clay or plastic.

This valve is a universal product due to its unique design, with a shaped, stainless steel reinforced flap that has an integrated mechanism that allows it to be sealed from backflow. This revolutionary product offers protection from flooding, rodents and noxious fumes.

The valve is WRc approved and certified.


**It fits 45 and 90 degree inlets on 450mm diameter chamber bases.  Not suitable for some 45 and 90 degree inlets on smaller 300mm diameter (or less) chamber bases – only the straight inlets on smaller chamber bases. This is due to the tight angled chamber walls restricting installation and operation.
NRV Chamber
NRV Open

What it does?

  • Stops backflow of effluent into properties, businesses and homes during flooding. Will be used extensively in properties on flood plains.
  • Stops rodents, frogs, snakes and other vermin from entering homes, businesses and other properties. Also prevents noxious fumes from entering properties. Ideally suited to the food and catering sector.
  • The flap has an inbuilt stainless steel plate to stop rodents biting through, providing efficient pest control.
  • A lockable flap allows you to close down entry pipes to inspection chambers to allow essential maintenance to be carried out.
  • The valve is completely re-usable when used for maintenance purposes.  The valve can be inserted while work is carried out then removed and used again.
  • The valve can open on a 45 degree bend due to its unique flap design.
  • The unique flap design also means the flap doesn’t catch on the chamber walls – which could restrict its movement and operation.
  • Unique funnel shaped body design means the flow of water is increased when passing through the unit; reducing blockages
  • Fits both Clay and Plastic 110mm or 4″ pipes.
Find the latest install guides and brochures on our Downloads Page