Skip to content 
Fundamentals
Filters are essential components across industries, designed to separate, purify, or refine substances by removing unwanted particles or contaminants. Whether in air, water, oil, or industrial processes, filters safeguard equipment, improve efficiency, and ensure product quality.
This glossary of filtration terms serves as a foundation for understanding the principles, types, and applications of filters. By clarifying technical language and core concepts, it helps engineers, technicians, and decision-makers navigate the world of filtration with confidence.
From basic definitions to advanced mechanisms, the fundamentals outlined here provide a clear pathway to grasp how filters work, why they matter, and how they contribute to cleaner environments and reliable operations.
Here are some key terms and concepts related to filters:
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
ABRASION: Migration of foreign material that enters the fluid stream from system components that wear from close tolerances, vibration or shock.
ABRASIVE: Any solid material such as grit with erosive properties.
ABRASIVES: Hard-structured strong solid.
ABSOLUTE: An arbitrary term used to describe a degree of filtration. The filtration industry uses various methods of determining absolute ratings which are not necessarily interchangeable. Generally absolute refers to 100% removal of solids above a specified micron rating on a single-pass basis.
ABSOLUTE: The sum of gauge pressure and atmospheric pressure.
ABSORB: To take up by cohesive, chemical or molecular action.
ABSORBENT: A filter medium that holds contaminants by mechanical means. Here one substance soaks completely through another, sometimes by undergoing a chemical change.
ACIDITY: The quality, state or degree being acid. In lubricating oils, acidity denotes the presence of acid-type constituents whose concentration is usually defined in terms of a neutralization number. The constituents vary in nature and may or may not markedly influence the behaviour of the fluid.
ADDITIVE: A chemical material usually added to a product to impart new or unusual characteristics or to improve existing characteristics.
ADSORB: To take up by adhesion of molecules of gases or dissolved substances to the surface of solid bodies resulting in a high concentration of the gas or solution at the place of contact. Gas or solution is condensed on the surface of the adsorbent, while during adsorption the material absorbed penetrates throughout the mass of the absorbent.
ADSORBATE: The material which is adsorbed i.e. the gas, vapor or liquid which adheres or is chemically attracted to the surface of the solid.
ADSORBENT: A material which adsorbs i.e. the solid which attracts and holds on its surface the gas, vapor or liquid components. Also, the materials added to liquors to decolonize or purify by adsorbing the colour or impure fuller’s earth, activated carbon, activate alumina, etc. which are all adsorbents.
ADSORBENT: A filter medium primarily intended to hold soluble and insoluble contaminants on its surface by molecular adhesion.
ADSORPTION: The natural phenomenon of a gas, vapor or liquid being attracted to and held on the surface of a solid. To some extent, adsorption takes place on any solid surface but certain materials have sufficient adsorbent capacity because of the finely divided material to make them useful in industrial applications such as the purification and separation of gases and liquids.
AGGLOMERATE: A group of two or more particles combined, joined or clustered by any means.
AGGREGATE: A relatively stable assembly of dry particles formed under the influence of physical forces.
AMBIENT: Surrounding.
ASME: American Society of Mechanical Engineers.
ASPHALTINE: Product of Partial Oxidation of Oil.
ATMOSPHERIC PRESSURE: The force exerted on a unit area by the weight of the atmosphere.
ATOM: Smallest particle of an element which retains properties of the element Example: Carbon atom.
AUTOCLAVE: Sterilizing apparatus which uses steam at high pressure.
