Backwash Drain Line Air Vent Design and Construct

Practical Engineering Australia was recently engaged by Seqwater to undertake an investigation and provide a solution for preventing an air pocket evolving in the backwash drain line during a filter backwash. This air pocket reduces free gravity water flow and causing water backing-up.

As part of Practical’s initial site investigations, temporary inline monitoring was installed to monitor the actual pressure occurring during operation of the backwash drain line.

With design information gathered from on-site testing, design of an air vent to  relief the air from the backwash drain line was completed while implementing feedback on additional functional requirements to the air relief solution. The final design of the air vent was installed utilising an existing flange connection while also providing a means to isolate the new air vent  through an isolating valve with extended spindle to allow operation from the original access platform. The finished pipework and valve were also colour matched to existing infrastructure to comply with Seqwater’s site cultural heritage requirements.

Final inspection and testing of the installation concluded that the installed air vent functioned as designed and complied with noise and operational requirements of the Seqwater site.

Should you have enquiries please contact our Sales Team on 07 3875 2133 or email