Page 265 - Parker - Hydraulic and Lube Filtration Products

Appendix

Defi nitions

Effl uent: Nominal Rating:
The fl uid that has passed through the fi lter. Micron size removed at a given effi ciency under a
manufacturer’s defi ned test condition. An arbitrary
Filter Medium: term assigned by manufacturers which varies and
The permeable material used for a fi lter that separates has therefore depreciated in value.
particles from a fl uid passing through it.
Pinched Pleat:
Flow Fatigue: A pleat closed off by excessive differential pressure
The ability of a fi lter element to withstand structural or crowding, thus reducing the effective area of the
failure of the fi lter medium due to fl exing of the pleats fi lter element.
caused by cyclic differential pressure.
Pleats:
Free Water: a series of folds in the fi lter medium usually of
Water droplets or globules in a system that tend to uniform height and spacing designed to maximize
accumulate at the bottom of a system’s fl uid because it effective area.
exceeds the solubility of the fl uid.
Pressure Line Filter:
Infl uent: A fi lter located in a line conducting working fl uid to
Fluid entering the inlet of a fi lter. a working device or devices.

In-Line Filter: Return Line Filter:
A fi lter in which the inlet, outlet and element are in a A fi lter located in the line which is conducting working
straight axis. fl uid form working devices to a reservoir.

L-Type Filter: Root:
A fi lter in which the inlet and outlet port axis are at The inside fold of a pleat.
right angles, and the fi lter element axis is parallel to
either port axis. Suction Filter:
A fi lter located in the intake line of a pump where the
Laminar Flow: fl uid is below atmospheric pressure.
Flow rate at which liquid is in a nonturbulent state
(10ft/sec) and should not exceeded to maintain T-Type Filter:
fi ltration integrity and consistency. A fi lter in which the inlet and outlet port axes are in a
straight line, and the fi lter element axis is
Media Migration: perpendicular to this line.
Contamination of the effl uent by fi bers or other
material of which the fi lter is constructed. Varnish:
Materials generated by the hydraulic fl uid due to
Micron: oxidation, thermal instability, or other reactions. These
A unit of length. Correct term is micrometer (µm), materials are insoluble in the hydraulic fl uid and are
which is .000039 inch. Human eye can see a generally found as brownish deposits in the work
40 micrometer particle. surfaces.

Neutralization Number: Y-Type Filter:
A measure of the acidity or basicity of a fl uid, this A fi lter in which the inlet and outlet port axes are in a
includes organic an inorganic acids or bases, or straight line, and the fi lter element is at an acute angle
combination thereof. to this line.

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