Non Return Valves (NRV)

The back-flow stop valve automatically closes when water or sewage flows back through the drain system during flood conditions. The stop valve allows normal sewage flow from the inlet to the outlet side of the valve with absolutely no flow restriction. Integral stop points in the wing area plus built-in flow channels combine to direct the sewage through the valve protecting the gate from soil contamination caused by sewage flow beneath the gate.

In the event of sewage backflow, the back surge is diverted to the 45-degree wings on the gate causing an upward lifting action. Once the lift occurs, the flow of water slams the gate into the closed position, protecting the entire plumbing system from sewage back surge. The gate has polyethylene foam inserts, which will float the gate into the closed position in a slow reversal of sewage back surge

The Mainline Fullport Backwater valve also has a built-in inspection cover to facilitate rodding of the main building drain.

• No problems with blockages
• Fullport normally-open design - NO FLOW RESTRICTION
• Virtually self-cleaning
• Installed on main building drain (or may be installed on branch)
• Showcase Gold winner - Canadian Institute of Plumbing and Heating

Kessel Staufix NRV

Non return valves or backwater valves are used within sewerage and drainage systems to eliminate the risk of flood damage by the backflow of sewage into properties through low level entries such as low level drain gullies, toilets and washing machine outlets. The Environment Agency in their publication on damage limitation for properties at risk from flooding and the Government guidance note “Preparing for Floods” both recommend the installation of non-return valves (anti-flooding devices) on all drains and sewers. Designed for connection to slid walled PVCu pipe these valves can be connected to other pipe materials using our wide range of coupling's (See Coupling's).

Building Regulations

Approved Document H, Para. 2.11

“Anti-flooding valves should preferably be of the double valve type, and should be suitable for foul water and have a manual closure device. They should comply with the requirements of prEN 13564. A single valve should not normally serve more than one building. A notice should be provided inside the building to indicate that the system is drained through such a valve. This notice should also indicate the location of any manual override, and include advice on necessary maintenance”

Keypoints: -

• 2-K Production Technology
• All Plastic Construction
• Easy To Install
• Meets BS EN 13564
• Perfect For Renovation
• Protects Against Backwater Flooding from Sewers
• Protects Against Rodents Entering Through Pipes
• Quick and Easy Pressure Testing
• Quick and Easy To Upgrade
• Stainless Steel Rodent Protection Flap (Optional)
• Tool Free Maintenance