Outlet Flap Valve, Anti Flood Non-Return Valve
Please note there are two versions of this valve, this is the outlet flap valve suitable for placing onto the end of plain ended pipe. The Inline flap valve version can be found here.
Non Return Valves for drainage and water pipes, available in two sizes 110mm and 160mm. Slips onto the end of pipes. Effective Anti-flood Valve and Rat Barrier Drain Protection.
What is a Flap Valve?
Flap Valves are innovative devices used to prevent flooding caused by the back flow of storm water and sewage. Backflow can be caused by intense rain, thaw or floods. The valves prevent backflow into residential and commercial premises via the drain systems, toilets or sewers. Effectively protecting rooms on lower levels against flooding caused by backflow of storm water and sewerage.
Where the Flap Valve has a metal Faceplates (like these), they are also an effective rat barrier to your drainage system. The metal stops the rodents from chewing through the flap faceplate of the non return valve and protects your plumbing system from rats and other rodents from entering buildings.
Flap Valves are installed on a pipe and allow water (and or solids if a soil or drainage pipe) to flow through the pipe as usual, but prevent anything from flowing back in, like flood water, rats or debris. The pressure of the water flowing through the pipe will open the valve, they automatically close when there is nothing flowing through the pipe.
Where Can flap valves be installed?
These flap valves are designed to be installed at the end of horizontal sewage pipes entering collection wells, cesspits or on drainage pipes leading storm water to soakaways or rivers. They are sometimes referred to as Outfall Flap Valves.
Available to fit either 110mm (4 inch) or 160mm (6") pipes.
Easy to install. The Non-Return Valve simply slips on to the end of the pipe. The O-ring within the Valve effectively jams the Flap Valve onto the pipe.
Technical Information
This flap valve is equipped with a chromium-nickel cover (A) protecting the flap and gasket. Additionally a chromium-nickel cover of the lever (B) has been designed into the Non-Return Valve to protect against rodents, atmospheric and the environmental conditions (eg. river flow). Flap valves have a rubber O-ring on the inside which ensures a tight fit of the valve to the pipe and effectively keeping the valve in place.
- Suitable for water, drainage or soil pipes
- Fits either 110mm or 160mm Pipes
- Fits over the outside of the pipe
- Installed at the end of the pipe
- Operation fully self-activating
- Plastic body: high quality polypropylene with increased UV resistance. The material is harmless to the environment and can withstand temperatures up to 95°C as well as resist aggressive chemicals.
- Stainless chromium-nickel stainless steel Faceplate
- Conforms to EN-13564-1:2004
Other Versions
- Flap Valves for Agricultural Land Drains are also available, fitting 72-100mm pipes,
- Inline Backflow Valves Valves for 50mm waste pipes,
- 110mm and 160mm Inline Backflow Valves for Horizontal pipes,
- 110mm and 160mm Inline Backflow Valves for Vertical Pipes.
If your query is related to an existing order please email in with your order number in the subject line. If you have a new residential enquiry please consult the online guides before calling as they may answer your question.
The delivery information page is divided into 1. Specific and 2. General delivery information below.
1. Specific Delivery Information relating to product lines- Small items dispatched daily with RM24 ~85% arriving next day
- Large items (UK made) typically 5 - 15 working days (Parcelforce/APC etc)
- 1,000 litre compact underground rainwater tank
- 250 litre Prestige large Plant Pot style planter Grey
- SAR40-TOP2 Wastewater Lifting station
- 250 litre Classic Slim Wall Water butt - Black Granite, Grey
- Hydraloop
- Green Roof sedum tray - pre planted option
- Madison 185 Litre rain barrel - Millstone
We're a Manchester based company and ship to the UK at our standard rates. Please get in touch requesting the delivery surcharge value if you are based in the Highlands or a UK island.
We no longer support ordering from the EU and Northern Ireland through the website. We can support ad hoc orders with limited liability.
Our design and Prestige range is available in the Netherlands, Ireland, Belgium, France, Germany, through our distributors.
Stock items will be dispatched on the day of order, if ordered before 1pm.
Letters are sent 1st class.
Parcels <2kg are shipped with Royal Mail 24 Tracked with the following target delivery times.
Guaranteed delivery can be arranged by advance agreement. This agreement is back to back with the courier and we will not be liable for any delays as per our terms.
A loss/replacement can only be pursued in line with the target delivery times of the courier or once the courier accept loss.
Bulky items (and pallet deliveries) are dispatched within 2-15 working days. We will request a contact number if this has not been provided at checkout.
Some items are made to order (bespoke) and details are given on the listing for dispatch times. If for any reason we anticipate a delay on our normal dispatch time we will contact you to let you know.
Occasionally there are delays. We shall not be liable for any direct or indirect losses, costs, damages or expenses incurred by you or any other person for any delays in delivery.
Missed deliveries where attempted delivery has been made usually result in re-deliveries the following day. The customer is responsible for organising re deliveries by contacting the courier direct.
Parcels/deliveries can only be "left out" if the delivering company allows that option. Parcelforce, for example, do not allow a parcel to be "left out".
We are an environment centric business and as such we try to minimise our waste. Our packaging is usually recycled and/or recyclable and we make efficient use of packaging to minimise wastage.
Covid delivery updates between 12.3.20 and 11.1.21 21 have been archived here.