Absolute Filter Rating:
The size of the largest spherical glass particle which will pass the filter under laboratory conditions
Often referred to as galling, scuffing, scoring or seizing. It happens when sliding surfaces contact one another, causing fragments to be pulled from one surface and to adhere to the other.
A filter medium primarily intended to hold soluble and insoluble contaminants on its surface by molecular adhesion.
This value may also be referred to as a Beta Ratio or Filtration Ratio. It is simply a ratio showing the relationship between upstream and downstream particle counts of a Ratio formula is used for calculating the efficiency of a filter media at removing particles, using base data from multi-pass testing
Burst Pressure Rating:
The maximum specified inside-out differential pressure that can be applied to a filter element without outward structural or filter-medium failure.
A system of filtration in which only a portion of the total flow of a circulating fluid system passes through a filter at any instant or in which a filter having its own circulating pump operates in parallel to the main flow.
By-pass Valve (Relief Valve):
A valve mechanism that assures system fluid flow when a pre-selected differential pressure across the filter element is exceeded; the valve allows all or part of the flow to bypass the filter element.
The number of contaminants a filter will hold before an excessive pressure drop is caused. Most filters have bypass valves, which open when a filter reaches its rated capacity.
A filter material made from plant fibers. Because cellulose is a natural material, its fibers are rough in texture and vary in size, and shape.
Structural failure of a filter element which can occur due to abnormally high-pressure drop or resistance to flow.
Any foreign or unwanted substance which can have a negative effect on system operation, longevity or reliability.
Any loss of performance due to the presence of contamination. Two basic types of contamination failure are Perceptible – gradual loss of efficiency of performance and Catastrophic – Dramatic, unexpected failure.
Migration occurs when the restriction is so great that the pressure pushes contaminant deeper in the media and eventually through the media and downstream.
A filter medium that retains contaminants primarily within tortuous passages.
Occurs when the restriction becomes so high that the element collapses or the media ruptures to relieve the upstream pressure
Any device or porous substance used as a strainer for cleaning fluids by removing suspended matter.
Occurs when the fluid upstream of a filter can pass to the outlet of the filter without going through the filter media, allowing contaminant to pass downstream.
Method of expressing a filter’s ability to trap and retain contaminants of a given size.
The porous cartridge, which performs the actual process of filtration.
A ported enclosure that directs the flow of fluid through the filter element.
The physical or mechanical process of separating insoluble particulate matter from a fluid, such as air or liquid, by passing the fluid through a filter medium that will not allow the particulates to pass through it.
The volume, mass or weight of a fluid passing through any conductor per unit of time
A mechanical means of removing and retaining insoluble contaminants.
A unit of length. One Micron = 39 millionths of an inch (.000039″). Contaminant size is usually described in microns. Relatively speaking, a grain of salt is about 60 microns and the eye can see particles to about 40 microns.
A filter element whose medium consists of a series of uniform folds and has the geometric form of a cylinder, cone, disc, plate, etc. Synonymous with “convoluted” and “corrugated”.
A throwaway-type bowl and element assembly that mates with a permanently installed head.
As the name implies, a strainer is a screen – like device fitted into a product line to prevent impurities in a fuel supply from flowing through to the fuel tank of a vehicle or airplane.
A property of a fluid that has to do with its resistance to flow and hence its rate of improvement.