How to prevent foul water backing up from the drainage system?

For a residential property in the UK, a 4 inch / 110mm drain non return valve will prevent foul water backing up the drain pipe from the sewage system. For commercial property, 6 inch / 150mm drain non return valve is required. The drain pipe will be found in the main drains inside an inspection chamber located outside your property. With the Buffalo Non Return Valve, the valve will fit in PVC or clay pipes. You may also want to consider a non return valve for sinks and baths, which have a 40mm waste pipe.

How does drain non return valve work?

The drainage non return valve can be inserted into the foul pipe inside the inspection chamber. The valve has a single flap, which is in the closed position most of the time. When water leaves the property, the flap opens and will close again once the pressure has rescinded. The valve is designed open with just the pressure from the flush of a toilet. In a flood event, or a back up of water due to blocked rains, the valve is closed shut to prevent back flow. In addition, a stainless steel flap stops rats in the drains.

Benefits of Drainage Non Return Valve

  • Anti-flooding solution, preventing backflow from entering your home from the sewage system.
  • Rat blocker for drains – a single stainless steel flap will stop rats climbing up the drains
  • Stop smells from the drains – with the single flap in the closed position a drain non return valve stops smells entering your property.

How to install a 110mm non return valve

  1. Locate the inspection chamber nearest to the toilet you are looking to protect
  2. Put on rubber gloves (included with every valve)
  3. Open the inspection chamber lid
  4. Flush the toilet to check which foul pipe you want to protect
  5. Simply push the 110mm non return valve into your chosen pipe