At a recent presentation made to the Institute of Public Works Engineering Australia in Canberra, Peter Klouda, Technical Support Engineer for Iplex Pipelines Australia made a comparison of PVC pipes and PE pipes in terms of sewer pipe performance.
Traditionally used for sewer systems as the material of choice for the past 37 years in Australia, PVC sewer pipes offer a good track record for performance to be gauged.
Sewers need to be fully sealed systems to overcome infiltration, exfiltration and tree root intrusion; occurrence of any of these issues can be very unpleasant for surrounding communities, and costly for the water authorities. The pipe system joint method and reliability therefore, are crucial factors in ensuring a well performing sewer system.
Klouda was responding to a question as to whether a polyethylene (PE) sewer system, which combines welded pipe and fabricated fittings would be an improvement on the existing PVC rubber ring jointed systems that have been of some concern to authorities and councils, especially about the risk of infiltration due to the rubber ring system.
The PE system has seen limited use in Australia over the past five years, and is not used elsewhere in the world for sewer systems. Klouda therefore wanted to explore whether there would be significant benefits in switching to a PE system with its different joint system.
Key findings of the PE Vs. PVC pipes comparison:
- PE pipes can cause a potential loss in flow of as much as 12% as they have a smaller internal diameter
- 60 – 80% percent of infiltration has nothing to do with the pipe system itself, and more to do with overflow relief gullies and illegal connections to the sewer
- PE pipe systems are 80% more costly to install than PVC sewer systems, partly because of the cost of the PE joints
- PE systems can end up 120% more expensive than PVC systems if house connection costs are added on
- PVC sewer pipes have a lower installation cost and lower repair cost
Klouda concluded that it was critical when choosing the right product for the system to determine its service life and overall costs including the cost of the pipe, installation costs, maintenance and repair costs, depreciation and the total asset cost. PVC pipes not only offer proven performance but also deliver on installation and repair cost factors.
The Vinyl Council of Australia is working to advance the sustainability of the vinyl/ PVC industry in Australia. Its members are drawn across the supply chain of the vinyl industry.