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Keralton Plumbing

Test Piston


Keralton Plumbing began in 1990. Since then, they have been committed to the plumbing industry while always improving processes and innovating the way they complete their work.

One issue that has always occurred in the plumbing industry is testing mixer cartridges and pipework to AS3500. We know many in the industry have issues testing to 1500kPA as cartridges are currently warranted to 800kPA which falls short of the Australian Standards. We find that testing the pipe work to AS3500 increasingly blows out and fractures the cartridges to the point they then need to be replaced, making it a costly exercise for any plumber.

When questioned on a job one day by the VBA to prove our testing was at AS3500 and to 1500kPA, again, our mixers blew out and needed to be replaced. Keralton Plumbing Project Manager Danial McFarlane knew there had to be a solution to the problem and a way to avoid the frustration of cartridge (and cost) blowouts. Danial created a prototype of the Keralton Plumbing Test Piston that would see him remove the mixer cartridge and replace it with the Test Piston. He could then effectively test to 1500kPA to ensure the pipework was solid with no damage to the mixer.

Interested to see how far we could push the Test Piston, he was able to factory test it to 3000kPA, well beyond any industry standard.

Encouraged by the idea and seeing how effective the prototype was, Keralton Plumbing embarked on obtaining a patent for the design.

Undergoing many modifications, the final design was settled on with the patent confirmed. The initial design was built for a 38mm cartridge, while it was later realised that to cover the majority of the tapware market a 34mm option also needed to be designed. A rubber gasket is an integral part of the design and is shaped in such a way as to allow water to flow through the mixer to the hot and outlet.

Both mould sizes were produced and the team was armed with these out on site to begin testing, to great success.

The straight forward installation allows all plumbers to easily use the product. Removing the current mixer cartridge, the rubber ring is place on the bottom of the plastic piston and installed into the cartridge housing. The test piston in then secured into the housing with the existing locking nut. Plumbers can now have the confidence to test their pipework to the required 1500kPA to be fully compliant with AS3500.


After numerous discussions with industry bodies and peers, Keralton Plumbing understands the importance of the test piston will have on the industry. It is believed that this is a major contribution to the plumbing industry to help plumbers have confidence in their work and reduce unnecessary costs while being 100% compliant with the Standards. Ideally, Keralton Plumbing would love to see this Test Piston sold with every new tapware mixer to allow for testing each and every time. By introducing this product into the plumbing market, Keralton Plumbing feel work is tested, leak issues are reduced, and the plumber and insurance companies can enjoy holding onto their profits.

Keralton Plumbing Test Pistons are sold exclusively by Keralton Plumbing. Available in both 34mm and 38mm, and come in packs of 10. These can be arranged for pick up from the Pakenham office at 1/27 Bate Close, Pakenham or can have postage arranged.

For any orders, please email



Test Piston 2


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