Kağıthane Backflow Valve Installation

A backflow valve lets waste water flow from the building towards the sewer, while its flap shuts off flow in the opposite direction. This stops dirty water from rising back up from the sewer and overflowing through the basement floor drain, the car park grate or the drain of a ground-floor shop. Fitting the valve somewhere you can reach it and checking it now and then for debris is part of the job too, because if the area in front of the flap gets blocked, it will not close fully.

On both sides of the stream valley in Kağıthane there are older apartment buildings lined up along steep streets, while the valley floor holds former industrial areas that have turned into offices, shopping centres and residences. In the low areas around the stream, street lines can fill up during heavy rain and cause backflow into basement floors. Because you are connected to the same infrastructure, backflow can start in your basement when the street line fills up, even if the neighbouring building has had no problem.

In a detached house or one with a garden, if the garden level sits below street level, the lowest drain is often the floor drain on the garden side. If foul water rises from it after rain, the valve can be fitted on the section of that line before it reaches the sewer. In a newer multi-storey residence, the kitchen and bathroom pipes of small flats connect to the shared stack through thin horizontal lines, and the basement and car park drains may also sit below street level. In buildings like this, the valve position is chosen at a point on the shared line that can be reached for maintenance, and it is fitted so that it does not hold back the waste water from the upper floors.