Average beta rating based on ISO 4548-12 multi-pass test methods: B100 = 25 (at 25 or greater micron, media is 99% efficient.) B75 = 20 (at 20 or greater micron, media is 98.7% efficient. Also considered absolute rating.) B5 = 10 (at 10 micron or greater, media is 80% efficient.)
The silicone anti-drain back valve prevents dry starts by preventing oil drain-back during shutdown. Silicone outperforms and outlasts standard rubber in both extreme cold and hot oil temperatures.
The wire backing is to support the filtration media. This further reduces the chance that the filter media could collapse. The use of stainless steel wire provides a strong, durable, AND low restriction way to provide the support.
The efficiency of a filter is described in terms of a percentage of particles caught at a certain particle size(and larger). Using the ISO 4548-12 multi-pass filtration efficiency test, Royal Purple filters are: -99% at 25 micron and larger -98.7% at 20 micron and larger -80% at 10 micron and larger