| Basket Strainer | Flow passes through a removable perforated basket or mesh element that captures solid particles. | Protecting pumps, valves, meters, and other downstream equipment. | Large debris, scale, rust flakes, weld slag, and other coarse solids. | Upstream of pumps, control valves, heat exchangers, and flow meters. | Simple construction, reusable element, low operating cost, and relatively easy cleaning. | The basket must be removed or cleaned when pressure drop increases; it is not intended for very fine filtration. |
| Y-Strainer | A Y-shaped body directs the fluid through a sloped cylindrical screen that retains suspended solids. | Continuous protection of equipment in compact piping layouts. | Sand, pipe scale, rust, and other relatively coarse suspended particles. | Near equipment in horizontal or vertical pipelines, subject to flow-direction requirements. | Compact design, broad availability, and suitability for liquids, gases, and steam when properly specified. | Screen capacity is limited; frequent cleaning may be required in heavily contaminated service. |
| Duplex Strainer | Two strainer chambers are connected with a changeover valve, allowing one chamber to operate while the other is cleaned. | Maintaining filtration without stopping the pipeline. | Coarse and medium-sized solid particles, including scale and process debris. | Continuous-process lines, fuel systems, cooling-water systems, and critical equipment protection. | Enables online element cleaning and reduces production interruptions. | Higher purchase cost, larger footprint, and more complex valve operation than a single strainer. |
| Cartridge Filter | Fluid flows through a replaceable cartridge made from materials such as pleated synthetic media, cellulose, or wire mesh. | Fine particle removal and final-stage protection. | Fine sediment, particulate matter, rust, and process solids; the exact range depends on the cartridge rating. | Downstream of coarse pre-filters and upstream of sensitive equipment or clean-process points. | Available in a wide range of filtration ratings and media types; provides consistent filtration. | Cartridges require replacement or cleaning, and pressure drop rises as the media loads with solids. |
| Bag Filter | Liquid flows through a fabric or felt bag, while suspended particles are captured within or on the filter media. | High-volume liquid filtration with relatively quick element replacement. | Suspended solids, sediment, rust, and process particles in liquid streams. | Process-water lines, cooling systems, chemical-transfer lines, and prefiltration stages. | Handles comparatively high solids loading and permits fast bag changes. | Generally used for liquid service; the bag must be replaced or cleaned when the differential pressure becomes excessive. |
| Automatic Self-Cleaning Filter | A control system detects rising differential pressure and initiates a cleaning cycle using backwashing, suction, brushing, or scraping. | Continuous filtration where manual cleaning would cause unacceptable downtime. | Suspended solids, organic matter, scale, and other particles depending on the cleaning design. | Industrial water systems, irrigation, cooling-water circuits, and continuous process lines. | Reduces manual intervention and can maintain filtration during operation. | Requires controls, actuators, a suitable drain or backwash arrangement, and regular inspection. |
| Coalescing Filter | Specialized media combine small liquid droplets or aerosols into larger droplets that can separate by gravity or drainage. | Removing liquid carryover from gas or compressed-air streams. | Oil aerosols, water droplets, and fine liquid mist. | Compressed-air systems, gas pipelines, instrument-air lines, and upstream of sensitive gas equipment. | Improves gas quality and protects pneumatic, measurement, and process equipment. | Requires correct flow velocity and drainage; excessive liquid loading can increase pressure drop and reduce performance. |
| Gas Separator or Knockout Filter | Flow velocity is reduced or redirected so that entrained liquid and larger solids separate from the gas and collect in a vessel. | Bulk removal of liquids and solids from gas pipelines. | Free liquids, condensate, sand, and larger solid particles. | Upstream of compressors, gas meters, regulators, and gas-processing equipment. | Provides high-capacity bulk separation and protects downstream equipment from liquid slugs. | Does not normally replace fine filtration; collected liquids and solids require controlled draining and disposal. |
| Magnetic Filter | Permanent magnets or magnetic elements attract and retain ferrous particles as the fluid passes through the housing. | Removing ferrous contamination from compatible liquid systems. | Iron filings, steel wear particles, and other magnetically responsive debris. | Lubrication systems, hydraulic circuits, cooling systems, and metalworking processes. | Reusable collection element, no disposable media, and low resistance when properly sized. | It does not effectively remove nonmagnetic solids, dissolved substances, or most organic contaminants. |
| Membrane Filter | A semi-permeable membrane separates particles or microorganisms according to pore size and the pressure-driven process used. | Very fine filtration, clarification, or microorganism reduction. | Fine particles, colloids, bacteria, and other retained substances depending on membrane type and pore size. | Water treatment, pharmaceutical processes, food processing, and high-purity fluid systems. | Can provide highly consistent separation and precise control of retained particle size. | More sensitive to fouling, requires pretreatment in many applications, and may need cleaning or replacement. |
| Activated Carbon Filter | Porous carbon adsorbs certain dissolved organic compounds, odors, chlorine, and taste-producing substances from the fluid. | Chemical polishing rather than ordinary particle removal. | Some organic compounds, chlorine, odors, and taste-related substances, depending on carbon type and contact time. | Water-treatment lines and selected liquid or gas purification systems. | Useful for adsorption-based treatment and improvement of odor or taste characteristics. | Adsorption capacity is limited; it does not remove all dissolved contaminants and requires timely media replacement. |