R+F

Filtration Glossary

Clear, concise definitions of the key terms in high-flow liquid filtration — from absolute filtration to condensate polishing.

226 O-Ring Interface

A common cartridge end-cap connection using dual 226-code O-rings with a locating fin or bayonet, sealing the element into the housing tube sheet.

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6-Inch Filter Housing

The predominant high-flow housing standard, accepting elements of roughly 6.0" (152 mm) outer diameter across most major OEM platforms.

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Absolute Filtration

A filtration rating stating that a defined percentage — typically 99.9 % (beta 1000) — of particles at or above the rated micron size is removed in a single pass.

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Beta Ratio (β)

A dimensionless number expressing filtration efficiency: the ratio of particles of a given size upstream to those downstream of the filter.

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Chemical Compatibility

The suitability of a filter’s media and seal materials for the fluid being filtered, over the operating temperature and pressure range.

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Condensate Polishing

The fine filtration of steam condensate to remove corrosion products (mainly iron oxides) before the water returns to the boiler.

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Dirt-Holding Capacity

The total mass of contaminant a filter element can retain before reaching its change-out differential pressure.

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End Cap (DOE / SOE)

The molded or welded cap that seals each end of a filter element and defines how it interfaces with the housing.

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Filter Change Interval

The recommended service period after which a filter element should be replaced, driven primarily by differential pressure rather than time alone.

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Flow Rate

The volume of liquid passing through a filter per unit time, usually expressed in m³/h or gpm, and a primary driver of element sizing.

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Glass Fiber (GF) Filter Media

A high-efficiency, absolute-rated pleated medium made from fine borosilicate glass microfibers, used for demanding fine filtration.

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High-Flow Filter

A large-format filter element designed to process very high liquid flow rates through a single cartridge, reducing the number of elements, housing size, and change-out labor compared with standard cartridges.

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MDEA / Amine Filtration

The filtration of amine solutions (such as MDEA) used in gas sweetening to remove acid gases like H₂S and CO₂.

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Meltblown Media

A depth-filtration medium formed by blowing molten polymer into fine, randomly layered microfibers that trap particles throughout the media thickness.

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Micron Rating

The nominal particle size, in micrometers (µm), that a filter is designed to remove — stated as either an absolute or a nominal value.

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Nominal Filtration

A filtration rating indicating an approximate particle-removal efficiency — commonly 50–90 % — at the stated micron size, without a guaranteed single-pass value.

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OEM Replacement Filter

A filter element manufactured to fit and perform equivalently to an original equipment manufacturer’s part, without being the OEM brand.

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Outside-to-Inside Flow

A flow configuration in which liquid enters the outer surface of the element and exits through the core, using the full pleat area for filtration.

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Pleated Filter Element

A filter whose media is folded into pleats to pack a large surface area into a compact element, lowering pressure drop and extending life.

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Polypropylene (PP) Filter Media

A thermoplastic filter medium prized for broad chemical compatibility, low cost and freedom from binders or additives.

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Pressure Drop / Differential Pressure (ΔP)

The difference in pressure between the inlet and outlet of a filter, indicating flow resistance and the degree of media loading.

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SDI (Silt Density Index)

A standardized measure of the fouling potential of water, widely used to protect reverse-osmosis and membrane systems.

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Verified Fit

An R+F designation confirming that a replacement element has been matched to the OEM part on dimensions, media, and end-cap/seal interface.

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Viton / FKM Seal

A fluoroelastomer O-ring or gasket material offering excellent resistance to oils, fuels, solvents and high temperatures.

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