The Comb Separator has undergone testing by the internationally recognised SRV (Screen Retention Value) test procedure.
This testing procedure was developed in the United Kingdom to compare under standardised conditions, the sewer solids capture efficiencies of the many commercially available screening devices.
In this testing program, the retention efficiency of the screens was determined under a range of spill flows and spill durations.
The SRV tests were conducted by an independent team of experts at a test rig at the United Utilities Plc, Warrington Waste Water Treatment Works using incoming sewage flows.
Following the installation of the comb screen assembly, the independent test team conducted a series of eighteen test runs. Each run used different flows that were pumped from the incoming sewer to the test rig. The flows were throttled by means of a downstream valve to vary the spill flow to the screen assembly. The efficiency of the screen was determined by measuring sewer solids captured at three locations in 4mm x 4mm mesh bags. At the end of each test run the bags were drained, weighed and recorded. The SRV was determined from a series of formula for each test run. Finally, the average
SRV, being the improvement afforded to the CSO chamber by the inclusion of the comb screen assembly, was calculated.