What does the FloPlast Non-Return Valve do?

The FloPlast D550 Non-Return Valve prevents sewage or stormwater from flowing back into the drainage system during floods or blockages, protecting your property from backflow damage.

Is the D550 suitable for 110mm underground pipes?

Yes. The D550 fits standard 110mm PVC-U underground drainage systems and connects via a push-fit socket joint.

Can I access the valve for cleaning?

Yes. It includes a removable inspection cover and a manual locking feature to hold the flap open during cleaning or inspection.

What's the purpose of the removable inspection cover on the D550?

The inspection cover allows you to access the valve for routine maintenance, cleaning debris from the flap mechanism, and checking the valve is operating correctly without excavating the entire installation.

How does the locking mechanism work when I need to clean the system?

The D550 features a secure locking flap that can be held in the open position during cleaning or maintenance work. This prevents the valve from closing whilst you're working on the downstream drainage system.

Can I install the D550 at any angle or does it need to be horizontal?

The valve must be installed horizontally with the flap oriented correctly to open in the direction of normal flow. Installing at an angle will prevent proper operation of the single flap mechanism.

What's the minimum flow rate needed for the flap to open properly?

The single flap design opens with minimal flow resistance under normal gravity drainage conditions. However, very low flow rates from small diameter connections may not provide enough pressure to fully open the flap.

Will this valve work with both foul water and surface water drainage?

Yes, the D550 is suitable for both foul and surface water applications, making it ideal for combined sewer connections where backflow from either source could occur during heavy rainfall or system surcharging.

How do I know which direction to install the valve in the drain run?

The valve body will have directional arrows indicating the flow direction, and the flap should open away from the property towards the main sewer. Installing it backwards will prevent normal drainage from working.

Can I connect the D550 directly to standard 110mm underground drainage pipe?

Yes, the D550 has standard 110mm socket connections that accept ring seal joints compatible with PVC-U underground drainage pipe and fittings.

What maintenance schedule should I follow for the D550?

Inspect the valve annually through the removable cover, checking for debris around the flap and ensuring it moves freely. Clean any accumulated sediment and verify the flap seals properly when closed.

The FloPlast D550 110mm Non-Return Valve (Single Flap) prevents wastewater backflow from entering underground drainage systems during flooding or surcharging.

Fitted inline within a 110 mm drain run, the valve allows normal flow outwards but closes automatically to block any reverse flow.
It’s an essential safeguard for properties prone to flooding or connected to combined sewers.

The D550 features a removable inspection cover for easy maintenance and a secure locking flap to hold the valve open during cleaning.

FloPlast 110mm Non-Return Valve (Single Flap)

£112.69

Quantity

Brand   FloPlast
SKU   D550
Type   Non-Return Valve – Single Flap
Diameter   110 mm
Material   PVC-U
Colour   Terracotta
Operation   Hinged single flap – automatic closure under backflow
Application   Prevents backflow in underground drainage systems
Standard   BS EN 13564-1 (Anti-flood devices)
Access   Removable top cover for inspection and cleaning
Guarantee   10 Years
Condition   New