After the driest winter on record for the metro area and with the public being asked to do their part to stop Perth drying out, fixing leaks in our infrastructure quickly is more important than ever.
But how do you fix a leak when the pipeline or the site cannot be shut down? On our sluice valves, we have started using a sealant which can be injected while water is still flowing through the system. It is a compound of Teflon and organic oil, and has so far been used for small and moderate leaks. A small injection hole is first drilled, and then the sealant is injected at high pressure into the ‘gland packing box’ of the valve using a hydraulic pump. The sealant flows around the packing box and fills any gaps, which stops leaks.
Recently, a substantial leak was detected in a valve in Medina, and the pipeline could not be shut down because of operational requirements. Excavation was arranged to gain access to the valve, and with the pipeline still in service, the sealant was injected. This completely stopped the leak and the valve remained useable. There have been some challenges in introducing the sealant, including bringing in the compound from the United States, gaining Department of Health approval to use it and bringing a representative from our supplier in Brisbane to Perth to demonstrate it’s use. The sealant has so far been used on 760mm water supply valves, but it has potential to be used on larger valves and also wastewater valves in the future.
“The sealant provides a cost effective way to maintain our valves, which also means we do not have to shut them down.” says Supervising Engineer with our Water Production Branch, Terry Willcocks. “Both Nathan Blight from Mechanical Services and Dave Hodson from PSN Water have done a great job and worked together to make the sealant available for maintenance of our valves.”