It is now a requirement for insurance companies that a pressure limiting is fitted to all water purifier systems to prevent high water pressure and water hammer ( caused by turning off cold water taps) from damaging the purifier cartridges and casings. It is recommended to replace these every 10 to 12 years to ensure both the internal components do not become clogged with calcium build up ( scale) as well as ensuring the rubber seals do not leak water.
Historically a lot of valves used were a white box shaped item which had a rubber diaphragm against a spring to control the pressure. We have found most of these leak water through the diaphragm, so now only use the cylinder shaped style such as the Apex model listed which is made in NZ. A picture of older models which should not now be in use is in the picture gallery.
Options include 350 and 600 KPA pressure ratings. Many other companies use the 350 kpa valves although we have found we get better water flows using the 600 kpa option which is set as the default. If flow speed is not important such as with a plumbed water cooler or hot water boiler, the 350 kpa option does give extra pressure protection.
