The backwater (non-return) valve protects lower located rooms against flooding caused by return flow of sewage waters. Such risk occurs most often in sanitary drainage systems connected to combined sewerage systems and in rainwater drainage systems. It may be caused by intense rainfall, thaw or flood.

The backwater valve prevents rats and other rodents entering the sanitary and rainwater drainage systems and, consequently, the building interiors. It protects also against unpleasant smells in case of longer breaks in system use.

• The Back-Flow Valve is simple to fit. 
• “Fit and Forget”.
• Operates fully automatically, no external power-supply needed
• Substitutes an inspection chamber, mounted at sewage system outlet from the building
• Resistant to effects chemicals and to hot wastewaters
• Permits temporary blocking of wastewater flow (for overhaul works)
• Maintains full flow capacity of the sewage system
• Easy to operate and to maintain.

Size - 110mm diameter £67.50 excl VAT.
Size - 160mm diameter £93.00 excl VAT.

Associated products, i.e. manhole covers, inspection chambers, etc. can also be purchased through UK Flood Barriers Limited.

The product is mad of high-quality polypropylene (PP), a very durable material that is mechanically resistant as well as resistant to aggressive effects chemicals and to hot wastewaters.

Cover mounting bolts of chromium-nickel stainless steel of OH18N9 type.

 Cover with overhaul-closure lever.

Cover and flap gaskets made of EPDM rubber with improved resistance to weather factors and ageing.

Smooth, suitably-profiled interior surfaces prevent gathering of sediments.

Flow cutoff flap with chrome-nickel guard protecting against rodents.

 

110 (ZB 110)
Connection diameter: 110 mm
Weight: 0.88 kg
Max operating temperature: 95°Ñ
Max operating pressure: 0.5 bar

160 (ZB 160)
Connection diameter: 160 mm
Weight: 1.89kg
Max operating temperature: 95°Ñ
Max operating pressure: 0.5 bar

CE  Product fulfills the requirements of European Standards EN 13564-1:2002

Registered industrial design

Backwater (non-return) valves are installed in horizontal drain pipes before a drainage-system outlet from a building, or in the house drain pipe, prior to its connecting to external sewer.

Most often they are mounted in inspection chambers.

The product is covered by a 24-month guarantee.  UK Flood Barriers cannot be held responsible for incorrect self-installation of product.

In order to ensure correct operation of the backwater valve, its functioning should be checked periodically. It should be done once a month and each time after intensive rainfall.
The check consists of manual switching of the backflow cutoff lever several times from OPEN (A) to CLOSED ( B) position. The lever should move smoothly between these two end positions.
If the lever moves with difficulty, or especially when it cannot be set to CLOSED position, it is necessary to perform servicing operations (see below).

The lever is to be left in OPEN position after the check.

In case of longer break in sewage system use, it is recommended to shift the backflow cutoff lever to closed position, in order to protect the rooms against any unpleasant smells.
The following maintenance operations are to be carried out every six months or in case of incorrect functioning of the backwatervalve:

1. make sure that the backflow cutoff lever is in OPEN position
2. unscrew 4 mounting bolts and remove the cover
3. clean all parts
4. check the condition of the gaskets, on the flap and under the cover. Replace them if necessary with original new Karmat gaskets (available from UK Flood Barriers).
5. grease the gaskets - silicon emulsions are recommended
6. re-install the cover and tighten the bolts with the torque of 5 to 7Nm 7.

the backflow cutoff lever should be left in OPEN position.