Screen Equipment Companies
Bar, fine, drum, step, and band screen manufacturers for headworks and pretreatment applications.
8 specialist providers · 52 related · 15 countries
Qualified suppliers come to you.
Filter results
Country
Industry
Technology
Not sure where to start?
Showing 1-20 of 60
Related providers
Listed for overlapping capabilities, not for screen equipment specifically.
Alfa Water srl
Italy · 51-200 employees
Alfa Water Srl is an Italian company with strong experience in designing and manufacturing all types of manual and automatic screen filters. We have invested our collective experience in water filtration to produce world-class solutions and products in stainless steel, super alloys and advanced materials. In addition to our deep knowledge in water filtration, Alfa Water Srl designs and manufactures a wide range of screen filters for the removal of suspended solids from water.
Buyer's guide
The buyer's guide to screen equipment
Screening Equipment for Wastewater: Bar Screens, Band Screens, and Fine Screening Technology
Screening is the first mechanical treatment stage in wastewater treatment, removing coarse solids (rags, plastics, wipes, food waste, grit) that would damage downstream equipment or cause operational problems. UK Sewers for Adoption 7th edition and BS EN 12255 (Wastewater treatment plants, Part 1: General construction principles) define screening standards. Screen types by aperture: coarse screens (greater than 20 mm, bar screens) protect inlet pumps; medium screens (6 to 20 mm, bar or band screens) protect fine screens and processes; fine screens (1 to 6 mm, step screens, drum screens); micro-screens (0.1 to 1 mm, band screens, rotating disc screens) for secondary effluent polishing or stormwater treatment.
UK standard for inlet works of WwTW greater than 250 PE: screens with maximum 6 mm aperture (EA Technical Standard on Screens, 2013 revision to IUK/EA/004); this addresses combined sewer overflow and consent compliance for SS (suspended solids). Manual bar screens (raked by hand): small pumping stations and emergency bypasses only. Mechanically raked bar screens (climber screens, chain-drive rakes, rotary drum): self-cleaning; continuous or timed operation; aperture 5 to 50 mm; screenings discharged to skip or compactor.
Fine and ultra-fine screens enable high-quality screening for both inlet works and tertiary treatment applications. Band screens: horizontal or inclined perforated stainless steel mesh belt (aperture 0.5 to 6 mm); wastewater flows through the band; solids captured on band surface; continuous spray wash removes screenings to discharge chute; suited to high-flow low-headloss applications. Step screens: vertical fixed and movable bars that step relative to each other to convey screenings upward; very low headloss; effective at 2 to 6 mm aperture; widely used in UK WwTW. Drum screens: cylindrical drum rotating in channel; wastewater passes through perforated or woven mesh surface; solids retained on drum exterior and washed off by internal spray; aperture 0.5 to 3 mm for secondary effluent polishing. Wipes and single-use plastics: a major screening challenge since 2015; fine screens less than 3 mm capture wipes that bar screens miss; UKWIR research (2019) showed 3 mm screens significantly reduce plastics reaching treatment stages. Screenings handling: screenings from municipal WwTW contain approximately 80 percent water content; compaction/dewatering in screenings press reduces volume by 50 to 70 percent; bagged or skipped for landfill or energy from waste; classified as waste under EWC code 19 08 01 (screenings).
Intake screens and fish protection for water abstraction: water abstraction intakes on rivers and estuaries require screening to protect fish and aquatic organisms (Water Framework Directive, Environment Act 1995, Salmon and Freshwater Fisheries Act 1975). EA Fish Pass Manual (2010) and National Fish Passage Assessment (2019) require through-screen velocity less than 0.1 m/s (at screen face) and aperture less than 1.5 mm to avoid impingement and entrainment of juvenile fish and larvae.
Drum/travelling band screens at river intakes: USEPA 316(b) equivalent guidance in UK; dual-flow band screens with fish-friendly design (low through-screen velocity, fish recovery bypass, gentle wash-off sluice); corrosion-resistant stainless steel (316L or duplex) for river intake service; automatic self-cleaning with backwash water recycled to maintain fish rescue system. Copper alloy screens (admiralty brass, copper-nickel alloy) have anti-biofouling properties for marine and estuarine intake screening, reducing cleaning frequency by 50 to 90 percent versus stainless steel in marine environments. Strainers for small process flows (DN50 to DN300): Y-strainers and basket strainers (100 to 500 micron mesh) protect instruments, valves, and flow meters.
Frequently asked questions
What aperture screen is needed at a wastewater treatment works?
UK screen aperture requirements: EA Technical Standard for WwTW Screening (IUK/EA/004 revised 2013): maximum 6 mm aperture at inlet works for all new or significantly upgraded WwTW; this captures rags, wipes, and plastics that would otherwise pass to biological treatment, causing foaming, digester problems, and effluent quality failures. Sewers for Adoption 7th edition: pumping stations serving greater than 250 PE: screen aperture maximum 6 mm ahead of pumps. Smaller pumping stations: 20 to 40 mm bar screens protect pump impellers, with finer screening (6 mm) at WwTW if serving. For secondary effluent polishing (where effluent re-enters watercourse): additional tertiary screening at 1 to 3 mm may be specified in EA permit conditions where water quality standards require very low SS (less than 10 mg/L) - particularly in bathing water catchments or chalk stream discharges. UK Water Industry Research (UKWIR): studies show 3 mm screens remove approximately 90 percent of fibrous materials (wipes, textiles) that reach the inlet works, compared to 50 to 60 percent removal by 6 mm screens. Fine screens (1 to 3 mm) are becoming more prevalent in new WwTW designs in the UK following UWWTD revised directive requirements.
What happens to screenings from wastewater treatment?
Screenings (material retained on intake screens at wastewater treatment works) are a regulated solid waste classified under European Waste Catalogue (EWC) code 19 08 01 (screenings from sewage treatment). Composition: primarily non-degradable materials flushed into the sewer - sanitary products (cotton, polyester), wipes (non-woven polypropylene, polyester, cellulose), cotton buds, plastic wrappers, food waste remnants, hair, grit; moisture content 60 to 90 percent as collected; 30 to 50 percent moisture after compaction/pressing. Volume: approximately 0.5 to 2 L per population equivalent per year at 6 mm screening; smaller apertures collect more material. Dewatering: most modern WwTW are fitted with screenings washing and compaction presses that wash screenings to remove faecal contamination and compress to reduce volume by 50 to 70 percent before discharge to skip. Disposal routes: landfill (most common, approximately 60 to 70 percent of UK screenings by weight); energy from waste (incineration, thermal treatment, approximately 20 percent); composting (minimal, screenings must be decontaminated and meet Animal By-Products Regulation requirements if food waste present). Microplastics in screenings: UKWIR research shows approximately 65 to 80 percent of microplastic fibres reaching WwTW are captured by 6 mm screens; finer screens capture higher proportions. Screenings are not classified as hazardous waste unless they contain defined hazardous substances.
How do fish screens work at water abstraction intakes?
Fish screens at water abstraction intakes prevent fish impingement (fish pressed against screen by flow) and entrainment (fish passing through screen) - both mortality risks regulated under UK and EU law. Fish-friendly screen design principles (Environment Agency Fish Pass Manual 2010, USEPA 316(b) guidelines): (1) Through-screen velocity: maximum 0.1 m/s at screen face (any point) prevents impingement of small fish (sprats, juvenile salmonids); larger travelling band screens with wider face area achieve lower velocity than small drum screens for same flow; (2) Aperture size: maximum 1.5 mm to prevent entrainment of larvae and eggs; 3 mm for adult fish protection in rivers without spawning; (3) Self-cleaning: continuous or frequent mechanical cleaning (internal spray wash or brush) removes marine fouling and maintains design through-screen velocity; fouled screens have higher effective velocity causing impingement; (4) Fish bypass: screens designed with a bypass channel or fish return sluice connected to downstream of abstraction to return impinged fish alive; (5) Screening of intake jets: micro-turbine intake jets or Archimedes screw intakes with bespoke screening; (6) Offshore or deep water intakes: used to draw intake water from below thermocline where fish density is lower. Materials: stainless steel 316L for freshwater; duplex or copper-nickel alloy for marine/estuarine. EA requires formal assessment of fish screening for new or modified abstractions under Environmental Permit or Abstraction Licence conditions.
What is the difference between bar screens and band screens?
Bar screens and band screens are both mechanical screening devices but differ in design, aperture range, and applications: Bar screens (fixed bar screens, mechanically raked): vertical or inclined parallel bars/plates with fixed gaps (typically 10 to 50 mm coarse, 5 to 15 mm medium); wastewater flows between bars; solids retained and raked upward by climbing rake, chain-drive, or rotary mechanism; screenings deposited in hopper or conveyor. Advantages: simple, robust, low maintenance; handles high debris loads (coarse trash); suitable for open channel inlet works. Band screens (travelling band screens): horizontal or inclined continuous moving mesh belt (woven mesh or perforated plate, aperture 0.5 to 6 mm); wastewater flows through the moving mesh; finer solids retained on band; internal spray wash cleans band continuously. Advantages: finer aperture capability (0.5 to 3 mm vs 5 mm minimum for most bar screens); lower headloss at fine apertures; automated operation; suited to secondary or tertiary polishing applications. Step screens: fixed and moving bars alternate in a step-like pattern; each step cycle moves solids upward; aperture 2 to 6 mm; low headloss; widely used for UK WwTW inlet 6 mm screening. Drum screens: cylindrical rotating mesh drum; wastewater inside or outside drum; compact; aperture 0.5 to 3 mm; used for fine screening of treated effluent or high-quality inlet screening. Selection: bar screens for coarse primary screening; band or drum screens for fine screening (less than 6 mm) where headloss must be minimised.
Illustrative scenario · Wastewater treatment inlet works, East Anglia
A composite drawn from typical projects in this category, not a single client engagement. Figures are indicative.
- Challenge
- A 120,000 PE wastewater treatment works in East Anglia was experiencing severe rag and wipe accumulation on aeration diffusers and digester heat exchangers, causing monthly cleaning shutdowns and GBP 85,000 per year in maintenance costs. The existing inlet works used mechanically raked bar screens with a 20 mm aperture, which passed the majority of flushed wipes and non-woven materials entering the combined sewer.
- Approach
- A step screen was installed at 3 mm aperture across the full inlet channel width (5.5 m), replacing the existing 20 mm bar screens. A washing and compaction press was added to reduce screenings volume before skip disposal. The design incorporated an emergency bypass channel with a manually raked 6 mm backup screen per EA Technical Standard IUK/EA/004.
- Outcome
- Downstream rag accumulation on aeration diffusers and heat exchangers reduced by 94 percent. Annual maintenance savings GBP 74,000. Screenings volume from skip increased by 35 percent (capturing previously-passed materials), but compaction reduced skip collection frequency from weekly to fortnightly, reducing disposal cost by GBP 8,400 per year. The 3 mm screen increased headloss by 120 mm at peak flow, within the available hydraulic gradient.
Questions to ask shortlisted providers
5
- 01
What is the design aperture, and has it been selected to meet the EA Technical Standard IUK/EA/004 requirement for WwTW inlet works?
EA requires maximum 6 mm aperture at inlet works for STWs; a 3 mm screen provides significantly better rag capture but requires more hydraulic head and more frequent cleaning; the choice must be documented in the design basis.
- 02
What is the maximum headloss across the screen at design peak flow, and does this require additional pumping or hydraulic gradient allowance?
Fine screens can cause 100 to 400 mm additional headloss at peak flow; this must be included in the hydraulic model to avoid nuisance flooding at the inlet works during storm events.
- 03
How are screenings discharged, and what dewatering, washing, and compaction equipment is included in the scope?
Un-dewatered screenings at 60 to 90 percent moisture content are unpleasant and expensive to dispose; a washing press reducing moisture to 50 to 60 percent and volume by 50 to 70 percent significantly reduces skip hire and disposal costs.
- 04
What is the manufacturer's recommended cleaning cycle and spray wash water consumption, and is the spray water recycled or discharged to drain?
Spray wash water consumption of 0.5 to 2 m3 per hour per screen is significant at small works; recycling spray water avoids direct consumption from potable supply, which may be the only available source at rural sites.
- 05
For river intake fish screens, what through-screen velocity does the design achieve, and does this comply with EA fish pass guidance?
EA requires less than 0.1 m/s through-screen velocity for fish-friendly intake screening; designs that achieve this at maximum abstraction flow protect the operator from EA licence condition breaches and fish impingement claims.
What drives cost in this category
4
- Aperture size and throughput capacity
- Coarse bar screens (20 mm, 1 to 10 m channel width) cost GBP 8,000 to 30,000 per unit; fine step screens (3 to 6 mm, similar width) cost GBP 25,000 to 80,000 per unit; the smaller aperture requires more frequent cleaning cycles and higher power, increasing OPEX by GBP 2,000 to 8,000 per year.
- Screenings handling and disposal
- Skip disposal of undewatered screenings at GBP 80 to 140 per tonne; a washing press reducing volume by 60 percent and moisture to 55 percent reduces disposal cost by GBP 5,000 to 20,000 per year at large works; payback typically 3 to 5 years for press capital cost of GBP 30,000 to 80,000.
- Channel width and number of units
- For channels wider than 3 m, multiple parallel screen units are required with intermediate guides; N+1 redundancy (one screen always available during maintenance) typically requires two to three screen units per channel, doubling or tripling capital cost.
- Material specification for corrosion resistance
- Stainless steel 316L wetted parts add 15 to 25 percent to screen capital cost versus mild steel with epoxy coating; marine or estuarine environments require duplex stainless or GRP for frame and casing components.
Key regulations and standards
4
- EA Technical Standard IUK/EA/004
- Environment Agency technical standard for screening of wastewater treatment works (revised 2013): maximum screen aperture of 6 mm required at inlet works for all new or significantly upgraded WwTW in England; applies as a permit condition or planning requirement for AMP capital schemes.
- Sewers for Adoption 7th Edition
- SfA 7th Edition (Water UK, 2020): pumping stations serving greater than 250 PE must include screening with maximum 6 mm aperture to protect pump impellers; screen design, headloss allowance, and screenings handling must comply with SfA before adoption by sewerage undertaker.
- EA Fish Pass Manual 2010 and WFD
- Environment Agency Fish Pass Manual (2010) and Water Framework Directive fish passage requirements: water abstraction intake screens must achieve through-screen velocity less than 0.1 m/s and aperture less than 1.5 mm to prevent fish impingement and entrainment; formal assessment required for EA abstraction licence or Environmental Permit condition.
- EWC Code 19 08 01 (Screenings)
- European Waste Catalogue code 19 08 01: screenings from sewage treatment are classified as non-hazardous waste; disposal requires registered waste carrier; annual waste returns submitted to the EA; screening must comply with Waste (England and Wales) Regulations 2011 duty of care requirements.
From the Insider