Common Filter Terms Defined:

PLAIN WEAVE: The most popular wire cloth weave. Each warp wire passes alternately over and under each fill wire. Each fill wire passes alternately over and under each warp wire. Warp and fill wire diameters are generally the same.  plain weave cloth
TWILLED WEAVE: Each fill wire passes over and under two warp wires at a time, and each warp wire passes over and under two fill wires at a time.  twilled weave cloth
PLAIN DUTCH WEAVE: The same pattern as plain weave, but the warp wires are of larger diameter than the fill wires. The fill wires are driven close to each other, making tapered or wedge shaped openings instead of square ones. The warp remains straight and the fill has all the crimps. plain dutch weave cloth
TWILLED DUTCH WEAVE: The same pattern as twilled weave, but the warp wires are of larger diameter than the fill wires. The warp wires are straight and the fill wires, driven up tight,have all the crimps, both up and down and sideways. Openings are wedge shaped. twilled dutch weave cloth
CELLULOSE: A porous paper used in the manufacture of filter media. Made from cellulose pulp derived mainly from wood or certain grasses. cellulose cloth
MICROGLASS Glass fibers fabricated in a unique manner by twisting, braiding, tapering, and splicing, with micronic precision to form filter media. microglass cloth
Absolute Filtration Rating: The diameter, usually in microns, of the largest solid particle which a specified filter media will pass.
Collapse Pressure: The maximum differential in pressure between two points in a fluid system usually as it relates to filtration. Expressed as ∆ (Delta P) between a housing inlet and housing outlet. This is important when it comes to proper filter maintenance.
Fluid Compatibility: The suitability of using the materials of a filter assembly, filter element, or seal in conjunction with a specified fluid.
Mean Flow Pore Size: Indicates that half the flow passes through openings of equal or smaller size and the rest flows through openings of larger sizes.
Mesh Rating: Indicates the number of openings in wire cloth per linear inch.
Micron Rating: A micron is equal to one millionth of a meter or .000039 (39 millionths of an inch). Expressed in convenient terms, 25 micron is equal to one thousandth of an inch (.0001).
Nominal Filtration Rating An arbitrary micron value established by a filter manufacturer as a realtive indication of average filtration capability. Based on Mean Flow Pore size.
PSI: Pounds per square inch. As it relates to filtration, it means the maximum operating pressure that a filter is capable of.
Rated Flow: The optimum flow rate for which a filter is designed.
SUS: Saybolt Universal Seconds. A measure of viscosity. The time in seconds for 60 cubic centimeters (CC) of fluid to flow through a standard orifice at a specific temperature.
Viscosity: A Measure of the internal friction or the resistance of a fluid to flow. The standard unit of measure is SUS or Centipoises.