As the filter operates for only eight or nine minutes (and in some cases less than eight) during the cleaning cycle, filter pressure is frequently overlooked and in some cases, never checked.

Machine operators may be unaware of the importance of filter pressure, usually because they have been trained to run the filter maintenance program on a daily basis or perhaps twice a week without reference to the pressure.

While standardised filter maintenance procedures ensure high filter pressure won’t develop, factors such as the number of loads processed, very heavy soil on some loads and operational problems such as excessive moisture in the solvent can cause very high pressure. Over a period of time the filter is blocked, resulting in costly maintenance. It is therefore worth making a point of checking filter pressure once a day or at least every two or three loads before running the filter maintenance program.

It is important when checking the pressure to ensure there is sufficient solvent in the cage to consistently maintain circulation through the filter.

Insufficient solvent will cause the pump to cavitate, causing filter pressure to fluctuate and so give an inaccurate reading.

Check the maximum recommended filter pressure in your operators manual. The maximum recommended pressure for most modern disc filters is around 1. 8 to 2.0Bar.