The standard alloy is 316L, with other alloys available. See Cleanable Stainless Steel Filter Elements below for more detailed information. The knife edge removes the contaminant from the surface of the element, and is drained periodically from the sump. 10 different micron ratings are available from 25 to 500 micron. Housing are available in carbon steel or 304 stainless steel with stainless steel elements.
Flow is from the outside in.
The openings between the wire winding and the degree of filtration are accurately and permanently established by the height of the projections. The wire is preformed to a wedge shape prior to winding to produce a tapered flow path opening inward. Particles larger that the openings between the windings are stopped at the outer surface where they are easily removed by a cleaning knife. The sump may be purged periodically to remove any contaminant.