North West Region has had instances where the Dual Check Valves (DCVs) have disintegrated and blocked the customers plumbing. The reason has been attributed to high chlorine levels combined with high ambient temperatures. The solution has been to change the material of the DCV, and no failures have been recorded to date.

Manufacturers of customer billing meters are now manufacturing meter bodies using polymer materials.

The wetted parts of the existing meters are manufactured using engineered polymers. Although there have been no reported failures due to degradation of the polymers, it would be good to confirm that the meters are lasting for the anticipated 15-year life

The Water Corporation would like to understand

  • The impact of high chlorine and ambient temperatures on different engineered polymers
  • Testing methodologies in determining the expected service life of various polymers

DCV failures.

During In-Service Meter testing failures of the dual check valves have been observed. These may or may not be related to water quality. Data is being collect on the performance of the dual check valves and is planned to be analysed using a vacation student. Another potential independent project or subset of the polymer investigation are the failure modes of the DCV’s.

  • Is it related to chlorine and temperatures?
  • There are O-rings/ seals in the DCV – are these failing or is it the main structure?

Note – to access Water Corporation sites, the appointed student will need to have received their first dose of COVID vaccine by 31 December, and their second by 31 January 2022. This is a requirement for all contractors working on Water Corporation sites. A vaccination certificate will need to be presented at Water Corp induction.