SOP - Backflushing the Flow Matcher Raw Sewage Pumps

Date: 2026 04-April 24

SOP: Flow Matcher Raw Sewage Pump Backflush

Topic

Backflushing the Flow Matcher raw sewage pumps.

When to Perform a Backflush

Backflush a pump that has been off for a week or more, before starting it.

Why Perform a Backflush?

In the pump building, detritus gathers near the pumps that are off. If a pump is started with detritus buildup at the pump intake, the solids will be pulled in immediately. This will cause excessive vibration of the pump. Excessive vibration will likely trigger the automatic cutoff switch, and the startup will fail. The process of backflushing is meant to push gathered detritus away from the pump, to reduce the chance of excessive vibration. In this way, we mitigate one of the factors that might prevent a successful Flow Matcher startup.

Which Controls are Involved in the Backflush Procedure?

1.      The hydraulic routing valve

2.      The ball valve

Steps

1.      Open the hydraulic routing valve clockwise, from 9 o’clock to 3 o’clock.

2.      Move the ball valve clockwise from open (parallel to the pipe) to closed (perpendicular to the pipe).

3.      Monitor the Allis-Chalmers Streamseal Valve position. A successful backflush will be achieved when the valve indicator is over 60% open for about 20 seconds.

4.      Once the Streamseal valve indicator has been above 60% open for about 20 seconds, return the ball valve to the open position.

5.      Return the hydraulic routing valve to the 9 o’clock position, lefty-loosey.