Non-Return Valve for 110mm, 160mm and 200mm Drainage Pipes

These Drain Non Return Valves (NRVs)/ Backflow Prevention Devices (BPDs) protect buildings against flooding from back flow of storm water and sewage travelling back up the sewage drain or toilet systems during intense rains, thaws, or floods.  BS8515 recommends the use of backflow prevention valves for underground rainwater systems to prevent sewage entering the rainwater tank. 

Suitable for Drain/Sewage Pipes as well as Water and Rainwater Pipes. The simple and effective design also inhibits unpleasant smells from the sewage or drainage system.

This backflow prevention device allos sewage or rain water to flow through it from one direction, but the flap closes tightly shut automatically when sewage or water pushes at it from the other side. KARMAT backwater valves are also equipped with a manual closure lever. Changing of the lever from OPEN position A to CLOSED position B causes a complete arrest of sewage backflow. The interior of the non return valve is smooth ensuring non-interrupted flow of sewage through the device.

The flap guard (as well as all assembly elements (screws, nuts, washers)) are made from corrosion resistant chromium nickel giving effective protection against rats and other rodents.

The backflow valves can be installed in horizontal pipes within the building or in manholes/access chambers outside the building.

Available in three sizes: 110mm, 160mm, 200mm

How does the Backflow Valve Work?

The Backflow Prevention Device has a Single Flap that allows sewage to flow through it from one direction, but the flap closes tightly shut when sewage or water pushes at it from the other direction. This simple mechanism ensures that, during flood events, basements and rooms located at lower levels are protected from sewage from the sewer system. It is a fully automatic operation that requires no external power supply and includes a lockable lever for emergency lockdown of the pipe network or for maintenance.

Returns

Unfortunately we cannot accept returns for this product when it has been fitted. If you are unsure as to whether this is the correct product for your system, please contact us before purchasing. We will happily offer free, impartial advice.

Technical Information

• Body Material: High Quality Polypropylene
• Single Flap design (contact us for Double and Triple Backflow Valves)
• Flap Guard Material: Corrosion resistant chromium nickel
• Screws, nuts, washers: Corrosion resistant chromium nickel
• Gasket Material: Rubber
• Self Operating (Automatic) Mechanism with Lockable Lever for emergency closure
• Suitable for Horizontal Sewage Pipes as well as Water and Rainwater Pipes.
• Maximum operating temperature 95°C
• Maximum operating pressure 0.5 bar
• Meets BS EN13564-1:2002
• CE Mark

Other Options

• Non-Return Valves / Backflow Valves for Vertical Pipes.
• Non-Return Valves / Backflow Valves for 50mm Pipes.