GRANGE Rexim, in partnership with German manufacturer Funke Kunstoffe, has developed a maintenance-free surge manhole system, whose automatic flushing system ensures pipelines are kept clean.
Installed into new or existing sewer or surface water drains, one surge manhole can service drain lengths up to 1,000 m.
Pre-assembled within a 1,000 mm deep by 1,200 mm diameter standard concrete manhole unit, the surge manhole has two integrated pieces, a 150 mm diameter flush water inlet on top, and a flush water outlet in a form of a bend in the manhole base unit.
The cistern's funnel shape forces a floating ball to roll into the bottom outlet, sealing the chamber. As soon as the cistern fills with rainwater, the ball is released and floats above the overflow channel resulting in one powerful flush of the sewerage system or surface water drain.
Cistern volume is adjustable from 400 to 750 litres per flush.
Grange Rexim says that from a catchment area of about 100 sq m with an assumed rainfall of 700 mm per year, the surge manhole will supply around 70 cu m of rain water, giving 50 to 100 flushes per year once installed. The system is maintenance-free and requires no energy input.