The pressure regulator of your high pressure jetting machine ensures a safe working environment. By using the hand wheel you can lower the water pressure to clean smaller or fragile drains or sewers. Also when using a spray gun, it is advisable (especially for machines with a bigger maximum workload) to reduce the pressure before you start to work with it. The automatic pressure regulator has a bypass-function which ensures that the overload of water gets back into the tank, when there is overpressure at the jetting nozzle. This usually happens when the nozzle inserts are blocked. This can cause potentially dangerous situations. Without a proper functioning pressure regulator, the water will automatically find another way-out, which could cause leakage, pump damage, or worst case an eruption in the high-pressure circuit or hose.
Due to the constant water flow, the pressure regulator is subject to wear, especially when working with contaminated water. After a while, the piston could wear and for this reason does not function properly anymore. That is why we highly recommend to check for damages at least once a year (or after 250 operating hours). You can take the piston out of its housing by unscrewing the central nut.
When there are damages (see image below), you need to change the piston body. At the same time, you can check the piston housing inside on possible damages.
When using clean water in the tank, the piston body is considerably less vulnerable for damages, comparing to the use of surface water. Because the system does not give a direct warning in case of wearing, you have to check the piston body regularly. As you know, safety comes first!