Page 174 - Parker - Process filtration

Glossary of Filtration Terminology
(Glossary continued)
Flux:
A relationship of fl ow to surface area; expressed
asgallons per minute per square foot.
“G” Style Bag:
Filter bag provided by Parker Process Filtration
Division to fi t many competitive vessels (FSI, AF&F,
GAF, ISP, etc.), which is referred to as a snap ring
seal confi guration.
Gauge Pressure:
Pressure greater than atmospheric pressure.
Gels:
Compressible or semisolid materials that can pass
through fi lter media at an undefi ned and inconsistent
degree. Best removed by depth medium.
Graded Density:
Variation in a cartridge that results in the fi lter
medium being more dense toward the core and less
dense toward the outside surface. This is useful
where a wide range of particle sizes exists because
it allows larger particles to be trapped toward the
surface and smaller particles toward the core.
Gravimetric Effi ciency:
Amount of contaminant removed by weight as
determined by suspended solids analysis
(ppm, mg/l).
Hydrophilic:
The tendency of a surface to wet with water
(water loving).
Hydrophobic:
The tendency of a surface not to wet with water
(water hating).
Immiscible:
Incapable of blending or mixing into a single
homogeneous phase.
Impingement:
Direct impact of particle or liquid upon the
fi lter media.
APPENDIX
Infl uent:
Fluid entering the inlet of a fi lter.
Laminar Flow:
Flow rate at which liquid is in a nonturbulent state
(10 ft/sec) and should not be exceeded to maintain
fi ltration integrity and consistency.
Mean Filtration Rating:
Average size of the pores of the fi lter medium.
Media (Medium):
Material in a fi lter element that separates solids
from fl uid.
Media Migration:
Contamination of the effl uent by fi bers or other
material of which the fi lter is constructed.
Micron:
A unit of length. Correct term is micrometer
(μm), which is .000039 inch. Human eye can see a
40-micrometer diameter particle.
Multipass Process:
A process or system in which fl uid is circulated
indefi nitely through a fi lter medium, e.g., engines,
compressors, hydraulic equipment.
Nominal Rating:
Micron size removed at a given effi ciency under a
manufacturer’s defi ned test condition. An arbitrary
term assigned by a manufacturer. Varies from 50%-
98% depending on manufacturer and product.
Particle Removal Effi ciency:
Removal of particles as a function of size as
determined by counting individual particles.
Permeability:
The property of a fi lter medium that permits a fl uid
to pass through under a pressure differential (such
asgpm/psi).
Porosity:
A measure of the open area of a fi lter medium.
Sometimes expressed as a void volume.
ENGINEERING YOUR SUCCESS.
174