Relatively new research results describe the risk of spark failure in oil systems and its consequences. When a non-electrically conductive liquid (eg oil) is pushed through a filter membrane (eg glass fiber or cellulose), there is a great risk of separating electrons, ie the generation of static electricity. This means that the filter is charged with a potential and the oil with the opposite.

Various parameters such as filter fineness, flow, viscosity etc. affect the charging potential and the charging time. In practice, it has been found that fine filters are almost always charged to the potential that spark discharges occur in both filters and oil tanks. However, few have observed the effects and you do not notice anything from the “outside” as all systems are in practice grounded. To show what is happening, we have isolated a filter with filter housing and grounded this via a “spark gap”.