Wedge Wire Screens: Technical and Commercial Questions
Quick answers about wedge wire screen types, standards, ordering, and ADEN Wedge Wire. For in-depth technical guides, visit our Knowledge Center.
Wedge Wire Fundamentals
What is a wedge wire screen?
A wedge wire screen is a precision filtration surface made by resistance-welding V-shaped (triangular) wire profiles onto support rods at exact intervals. The slot widens inward so particles either stay on the surface or pass completely through, eliminating internal clogging. It produces a rigid, one-piece welded structure with thousands of uniform continuous slots.
Wedge wire screens are also known as profile wire screens, V-wire screens, and continuous slot screens. The name comes from the triangular (wedge-shaped) cross-section of the wire itself. Each wire is positioned with its narrow edge facing the flow. The slot widens continuously behind the surface. A particle that enters the slot opening passes through completely -- nothing traps it inside. Every slot is identical in width, welded into a single rigid unit. Key differences from alternatives include no loose ends (unlike woven mesh), no crossing wires (unlike woven mesh), and no punched holes (unlike perforated plate). Originally developed in the 1930s for groundwater wells, wedge wire is now standard across water treatment, food processing, mining, oil and gas, pulp and paper, chemical processing, and dozens of other industries.
What does "continuous slot" mean and why does it matter?
In a continuous slot screen, V-wire runs uninterrupted across the entire screening surface with no gaps, seams, or breaks. This produces perfectly uniform flow distribution with no dead zones, distributes mechanical loads across thousands of weld points instead of concentrating stress at hole edges, and prevents localized solids accumulation.
Continuous slot matters for three reasons. First, uniform flow distribution means liquid enters evenly across the full screen length, eliminating dead zones where solids would accumulate. Second, structural efficiency means continuous wire distributes load across thousands of weld points, rather than concentrating stress at individual hole edges as in perforated plate. Third, there are no weak spots because there are no seams or interruptions that could become failure initiation points. Continuous slot design was originally developed for groundwater well screens in the 1930s. Uniform flow entry across the entire well screen surface prevents localized sand movement, which causes formation collapse and sand pumping. This same principle applies in every modern application, from intake screens to centrifuge baskets to sieve bends.
What do the terms FOTI and FITO mean?
FOTI (Flow Outside To Inside) means liquid flows from the outer surface inward, with V-wire facing outward -- used in intake screens and well screens. FITO (Flow Inside To Outside) means liquid flows from inside outward, with V-wire facing inward -- used in rotary drums and centrifuge baskets. The narrow edge of the V-wire must always face the incoming flow.
FOTI stands for Flow Outside To Inside, where flow goes from the outer surface inward with V-wire facing outward. Typical applications include water intake screens, well screens, and submerged screens. FITO stands for Flow Inside To Outside, where flow goes from the inner surface outward with V-wire facing inward. Typical applications include rotary drum screens, centrifuge baskets, and pressure vessels. The critical rule is that the narrow edge of the V-wire must always face the incoming flow. This ensures the slot widens in the direction of flow, so particles either stay on the surface or pass completely through. Specifying the wrong flow orientation reverses the slot geometry and eliminates the self-cleaning effect, turning every slot into a particle trap.
Why are wedge wire screens resistant to clogging?
The V-wire cross-section creates a slot that is narrowest at the surface and widens continuously behind it. A particle either cannot enter (oversized) or enters and passes completely through (undersized) -- nothing traps it mid-slot. Only two contact points exist at the surface versus four in woven mesh, which virtually eliminates near-size particle blockage.
The anti-clogging mechanism works through four principles. First, the narrowest point is at the surface, making the slot opening the tightest restriction. Second, continuous widening behind the surface means once a particle enters, the gap only gets larger. Third, only two contact points exist compared to four in woven mesh square openings. Fourth, no internal ledges or geometry exists inside the slot to catch or hold particles. Research on screen plate geometry confirms that V-wire slot design virtually eliminates near-size particle blockage in granular solid-liquid separation. Limitations exist: fibrous materials can bridge across slots, sticky or adhesive substances can adhere to wire surfaces, and biological growth (biofouling) can reduce effective slot width over time. For granular solid-liquid separation, V-wire provides measurably superior resistance to blinding compared to any flat-surface alternative.
What are the key advantages of wedge wire screens?
Wedge wire screens offer seven core advantages: non-clogging V-slot geometry, highest open area at equivalent separation (15-65%), permanent slot accuracy from welded construction, one-piece structural strength, wide material availability (304 to Super Duplex), exceptional design flexibility (9+ screen types), and long service life with low total cost of ownership (8-25+ years).
Non-clogging slot geometry uses a V-profile creating two contact points with a widening gap so near-size particles cannot wedge. Highest open area of 15-65% compares to 20-35% for perforated plate at equivalent separation. Permanent slot accuracy from welded construction does not stretch, deform, or shift under load. Structural strength comes from a one-piece welded unit that handles vibration, pressure, and impact. Wide material range spans SS 304 through Super Duplex 2507 plus carbon and alloy steels. Design flexibility includes 9 wedge wire screen types plus 5 drilled screen hole geometries. Long service life of 8-25+ years delivers dramatically lower total cost of ownership than alternatives. These advantages compound in practice. Higher open area reduces equipment size. Non-clogging geometry reduces maintenance. Permanent slots eliminate re-calibration. The result is lower lifetime cost in virtually every application.
Screen Types
What types of wedge wire screens exist?
ADEN produces 10 wedge wire screen configurations -- cylindrical (Johnson Screen), flat panel, sieve bend, rotary drum, looped, basket, intake (T-Screen), water well, and Coanda -- plus a complementary drilled screen line with 5 hole geometries for specialized industrial applications.
Cylindrical (Johnson Screen) is helically wound V-wire on longitudinal support rods, the most widely produced with continuous slot for water wells, oil/gas sand control, and process filtration. Flat panels are rectangular up to 1500 x 3000 mm for vibrating screen decks, drain plates, and architectural use. Sieve bend (DSM) is a curved static panel that is gravity-fed for mineral dewatering, starch recovery, and wastewater. Rotary drum is a slowly rotating cylindrical screen for municipal pre-treatment and food processing. Looped screens have V-wire looped around support rods for extreme mechanical strength in heavy-duty mining. Baskets are precision-machined cylinders for centrifuge separation in sugar and chemicals. Intake (T-Screen) is submerged and passive with low approach velocity for fish-safe raw water intake. Water well screens use continuous-slot cylinders sized to formation D10. Coanda intake is a curved self-cleaning panel with no power or moving parts. Filter nozzles are compact wedge wire elements used in resin traps, underdrain systems, and ion exchange vessels. Header/lateral systems are small-diameter cylinders with hub connections for ion exchange and activated carbon beds. ADEN also manufactures drilled screens with cylindrical, bi-cylindrical, countersunk, conical, and cylindrical-conical hole geometries.
What is a Johnson screen?
"Johnson screen" is the most widely recognized trade name for cylindrical wedge wire screens, originating from the Johnson Division of UOP, which pioneered continuous-slot well screens in the 1930s. It has become a generic industry term -- like "Aspirin" or "Xerox" -- used regardless of manufacturer.
The Johnson Division of UOP (later Aqseptence Group) developed the continuous-slot well screen in the 1930s in the United States. Their design of helically wound V-wire welded to longitudinal support rods became the industry standard for groundwater and oil well applications. Over decades, "Johnson screen" became a genericized trademark. When you see it in specifications, RFQs, or engineering documents, it refers to any cylindrical wedge wire screen with helically wound V-wire (triangular profile wire), longitudinal support rods, and continuous slot construction. ADEN manufactures this exact screen type in any diameter, length, material grade, and slot configuration, fully interchangeable with any OEM specification calling for a "Johnson screen."
Standards & Compliance
How do wedge wire screens protect fish and aquatic life?
Wedge wire intake screens protect aquatic life by maintaining through-slot velocity below 0.5 ft/s (0.15 m/s) and using slot apertures of 2-3 mm to physically exclude juvenile fish. Large surface area keeps approach velocity low, while ambient currents sweep organisms safely away from cylindrical T-screen surfaces.
Critical design parameters include through-slot velocity below 0.5 ft/s (0.15 m/s) per regulatory guidance, slot aperture of 2-3 mm for juvenile fish exclusion, surface area oversized to reduce approach velocity to safe levels, cylindrical T-screen type that allows ambient current to sweep organisms away, and air backwash cleaning that maintains clean screen surface without harming aquatic life. The regulatory framework includes US CWA Section 316(b) requiring Best Technology Available for cooling water intakes, UK Environment Agency requiring 3 mm positive exclusion for eel and fish protection, and EU Water Framework Directive for ecological status protection of water bodies. Peer-reviewed field research confirms wedge wire screens are among the most effective passive intake technologies for aquatic life protection with no impingement and no entrainment when properly designed.
What is API 19SS?
API 19SS (also published as ISO 17824) is the global specification for wire-wrapped sand control screens used in oil, gas, and water wells. It defines requirements for materials, slot tolerances, mechanical testing (axial load, collapse, burst), and manufacturer quality systems. Major oil companies require compliance for all downhole screen purchases.
API 19SS covers every critical aspect of well screen manufacturing and performance: base pipe material requirements and traceability, wire wrap material specifications and compatibility, slot width tolerances and standardized measurement methods, end connections including thread type, dimensions, and pressure ratings, mechanical testing for axial load capacity, collapse pressure, and burst pressure, and quality management system requirements for manufacturers. The standard applies whenever wedge wire screen is purchased for downhole well completion, sand control, or gravel pack service. It is required by major oil companies, national oil companies, and well service companies worldwide. API 19SS ensures safe performance under extreme pressures, temperatures, and mechanical loads encountered in well environments. ADEN manufactures well screens to API 19SS requirements and provides full compliance documentation with each order.
What is US CWA Section 316(b)?
US Clean Water Act Section 316(b) requires cooling water intake structures to use the best technology available (BTA) for minimizing environmental impact on aquatic organisms. In practice, this means intake screens must maintain through-slot velocity below 0.5 ft/s (0.15 m/s) with 2-3 mm slots and air backwash capability.
Section 316(b) sets the regulatory baseline for intake screen design in the United States. The practical requirements for compliance are through-slot velocity below 0.5 ft/s (0.15 m/s), slot size of 2-3 mm typical, cylindrical T-screen geometry with in-stream mounting, air backwash cleaning system for debris removal, and approach velocity that must not impinge or entrain organisms. Similar regulations exist in other jurisdictions: UK Environment Agency fish screening guidelines, Canada Fisheries Act and DFO screen regulations, and EU Water Framework Directive. ADEN intake screens are designed with 316(b) compliance as the baseline, ensuring regulatory acceptance across multiple jurisdictions with a single design approach.
Do wedge wire screens meet food-contact and sanitary standards?
Yes. ADEN screens use SS 316L with CIP-compatible surface finishes, no crevices or dead zones, and no non-metallic coatings or adhesives. There is no single universal "food-grade certification" -- standards vary by country and product type. ADEN manufactures to specific material, surface finish, and documentation requirements per the applicable regulatory framework.
Wedge wire screens satisfy food-contact requirements through material selection and fabrication practice, not through a single blanket certification. ADEN uses SS 316L (EN 1.4404) as the standard for food contact, CIP-compatible surface finish with mechanical polish or electropolish available, geometry with no crevices, dead zones, or particle traps, no non-metallic coatings or adhesives, and material certificates and surface finish reports per jurisdiction. For each project, ADEN provides the appropriate compliance documentation per the local regulatory framework -- whether that is FDA (US), EC 1935/2004 (EU), or other national standards. Key industry frameworks include 3-A Sanitary Standards, EHEDG guidelines, and ASME BPE for pharmaceutical applications.
Do screens comply with EU drinking water contact regulations?
Yes. All stainless steel grades used by ADEN are listed on the European Positive List (EUPL) under Commission Implementing Decision (EU) 2024/367, implementing Article 11 of Directive (EU) 2020/2184. EUPL entry 1679 approves EN 10088 stainless steels for all product groups (A through D) in contact with drinking water.
The EU regulatory framework for materials in contact with drinking water was modernized under Directive (EU) 2020/2184, which replaced the former Directive 98/83/EC. The EUPL became the definitive approved materials list. AISI 304/304L (EN 1.4301/1.4307) is approved for Groups A-D for fresh water and low chloride. AISI 316/316L (EN 1.4401/1.4404) is approved for Groups A-D for chlorinated water and brackish. Duplex 2205 (EN 1.4462) is approved for Groups A-D for high-chloride and desalination. Super Duplex 2507 (EN 1.4410) is approved for Groups A-D for seawater and aggressive chemistry. The EUPL framework applies from 31 December 2026. ADEN provides mill certificates (EN 10204 3.1) with every order, confirming material composition and traceability. For non-EU projects, the same stainless steel grades typically satisfy equivalent national drinking water regulations in the UK, Australia, and other markets.
Are wedge wire screens recyclable?
Yes -- wedge wire screens are 100% recyclable. They are made entirely from stainless or carbon steel with no coatings, resins, or composite materials. A screen with a 15-year service life uses approximately one-fifth the total material of a replacement cycle using 3-year alternatives, making wedge wire one of the most sustainable filtration technologies available.
Environmental benefits extend well beyond end-of-life recycling. The material is 100% recyclable stainless and carbon steel with no coatings, resins, or composites to separate. Reduced material consumption means a 15-year screen replaces 5 screens on a 3-year cycle. No consumable filter media eliminates ongoing waste from disposable elements. Lower energy use comes from higher open area meaning lower pressure drop and reduced pumping energy. Aquatic protection through intake screen designs protects fish and organisms at water sources. Full traceability through material certificates supports responsible sourcing requirements. The circular economy advantage is significant: stainless steel retains its material properties through unlimited recycling cycles, and the scrap value of a retired screen offsets a portion of replacement cost.
Ordering & Delivery
Does ADEN sell stock / off-the-shelf screens?
No. ADEN is 100% custom manufacturing with zero stock inventory. This is a deliberate philosophy: every screen must match the application exactly in slot aperture, wire profile, material grade, dimensions, and connections. The process moves from application parameters through engineering, approval, manufacturing, inspection, to shipment.
The ADEN custom manufacturing process has seven steps. First, application parameters are defined where the customer provides operating data. Second, an engineering specification is developed with review and discussion. Third, technical drawings are issued for the customer to review dimensions and details. Fourth, written approval requires the customer's sign-off. Fifth, ADEN handles manufacturing and production. Sixth, inspection and quality control reports are made available. Seventh, shipment with full documentation is sent for the customer to receive and verify. A screen with the wrong slot, wrong material, or wrong dimensions is not just suboptimal -- it can cause process failure, equipment damage, or regulatory non-compliance. ADEN's zero-compromise approach ensures every screen is engineered for its specific duty.
What determines wedge wire screen pricing?
Five factors drive pricing: material grade is the largest cost driver (Super Duplex costs 40-80% more than 304), followed by geometry and complexity, slot aperture and wire density, order quantity for setup cost amortization, and surface treatment requirements like electropolishing.
Material grade is the largest driver, with 304 as baseline, 316L at +15-25%, Super Duplex 2507 at +40-80%, and exotic alloys priced per project. Geometry and complexity have high impact, ranging from flat panel (simplest) through standard cylinder to tapered basket with machined end rings (most complex). Slot aperture and wire density have moderate impact, where finer slot means more wire per square meter, more welds, and slower production speed. Quantity has moderate impact as setup costs are amortized across batches with volume pricing available for repeat orders. Surface treatment has low-to-moderate impact, where electropolishing, specific Ra surface roughness requirements, or coatings add processing steps. To optimize cost, specify only the material grade you need, standardize dimensions across your facility where possible, order in batches to leverage setup cost amortization, and discuss alternatives with ADEN engineering for more cost-effective designs.
What are typical lead times?
Standard screens in common materials ship in 2-3 weeks from drawing approval. Complex or large screens take 5-8 weeks, specialty materials (Duplex, Super Duplex, exotic alloys) require 6-10 weeks due to mill lead times, repeat orders take 2-3 weeks, and urgent small-quantity orders can ship in 1-2 weeks if material is in stock.
Standard orders with common material and moderate complexity ship in 2-3 weeks for SS 304 and 316L in typical sizes. Complex or large screens with large diameters, tight tolerances, or complex end fittings take 5-8 weeks. Specialty materials including Duplex, Super Duplex, and exotic alloys require 6-10 weeks where mill lead time for raw material is the primary driver. Repeat orders with the same specification on file take 2-3 weeks since drawings and approvals are already complete. Urgent small quantity orders with material in stock can ship in 1-2 weeks, subject to production schedule availability. All lead times are measured from written drawing approval, not from initial inquiry. Every ADEN quotation includes a confirmed delivery date. For time-critical projects, discuss schedule requirements early so material can be pre-ordered if needed.
What documentation and certifications does ADEN provide?
Every screen ships with a Certificate of Conformity (covering material, dimensions, slot, and drawing compliance) and a Material Test Report / MTR (chemical composition, mechanical properties, full heat traceability). Additional documentation -- dimensional inspection reports, weld procedures, food-contact or API 19SS certifications -- is available on request.
ADEN operates under an ISO 9001:2015 quality management system. Standard documentation included with every screen consists of a Certificate of Conformity confirming material grade, dimensions, slot aperture, and compliance with approved drawing, plus a Material Test Report (MTR) with chemical composition, mechanical properties, and heat number traceability per EN 10204 Type 3.1. Additional documentation available on request includes dimensional inspection reports for tight-tolerance or critical applications, weld procedure documentation (WPS/PQR) for code-compliant fabrication, food-contact certification for food and beverage applications per EC 1935/2004 and FDA, 316(b) compliance documentation for US environmental intake screen projects, API 19SS certification for oil and gas downhole screens, and project-specific certifications as defined in purchase order or contract. English is the default language for all documentation, with other languages available on request.
Does ADEN ship internationally?
Yes -- ADEN ships worldwide from its Istanbul, Turkey manufacturing facility, with a Sindelfingen, Germany office supporting EU logistics. Packaging includes individual wrapping, wooden crates or pallets, moisture protection for ocean freight, and custom crating for oversized or fragile screens. Standard Incoterms (EXW, FOB, CIF, DDP) are all accommodated.
ADEN manufactures in Istanbul, Turkey with a EU logistics office in Sindelfingen, Germany. Each screen is individually wrapped, packed in wooden crates or pallets with custom crating for oversized or fragile items. Ocean freight includes moisture barrier protection using VCI or desiccant. All standard Incoterms are accommodated including EXW, FOB, CIF, and DDP per customer preference. ADEN's Istanbul location provides efficient access to Europe, the Middle East, Africa, and Asia by sea, with competitive air freight options for urgent or small shipments worldwide.
What information does ADEN need for a quotation?
If you have a drawing, provide the technical drawing plus material specification, quantity, and delivery location/timeline. Without a drawing, provide your application description, operating environment (temperature, pressure, pH, chemicals), dimensions, material preference, quantity, particle size data, flow rate, and any regulatory requirements. Or simply describe your process problem.
With a drawing (fast track), provide the technical drawing in PDF, DWG, or dimensioned sketch format, material specification, quantity, and delivery location and timeline. Without a drawing (engineering consultation), provide as much as possible: application description of what you are screening, filtering, or separating; operating environment including temperature, pressure, pH, and chemical exposure; dimensions or available space or existing screen measurements; material preference or let ADEN recommend; quantity; particle size data such as sieve analysis or grain-size distribution; flow rate including design and maximum; equipment make and model if the screen fits existing equipment; and regulatory requirements such as API, 316(b), or food-contact. If you do not have technical details, describe your process problem -- what you are trying to achieve, what is not working, or what you need to improve. ADEN's engineering team will help define the right screen specification. Response time is 1 business day.
About ADEN
Where is ADEN Wedge Wire located?
ADEN operates from three locations: Istanbul, Turkey (Pendik) for manufacturing, all production from wire profiling through final inspection; Sindelfingen, Germany for European sales, logistics, and technical consultation; and Teknopark Istanbul for design, R&D, and material testing. Products ship worldwide from Istanbul.
Istanbul, Turkey (Pendik) serves as the manufacturing headquarters with wire profiling, resistance welding, surface treatment, quality control, and final inspection. Sindelfingen, Germany operates as the European office handling sales, logistics coordination, and technical consultation. Teknopark Istanbul is the R&D center for custom solutions design, material testing, and engineering development. This three-location structure delivers a strategic combination: Turkey's manufacturing cost advantage for competitive pricing, EU commercial presence for European market accessibility and support, and a dedicated R&D facility for continuous innovation. All finished products ship worldwide from the Istanbul manufacturing facility.
What makes ADEN different from other wedge wire manufacturers?
Three fundamentals set ADEN apart: direct engineering access with no sales layer between customer and design/manufacturing engineers, 100% custom manufacturing with zero stock screens (every screen engineered for its specific project), and ADEN-GROUP multi-company engineering resources backing specialist wedge wire focus. The result is technically precise solutions delivered in 12 screen types across 10 material grades to 30+ countries.
Direct engineering access means customers speak directly with design and manufacturing engineers with no sales intermediaries. 100% custom manufacturing means zero stock screens where every screen is engineered and built for its specific application and project. ADEN-GROUP resources provide a multi-company engineering group with depth in materials, process engineering, and R&D. The range covers 12 screen types and 10 material grades with global reach to 30+ countries across 5 continents and response time of 1 business day for initial response. The zero-stock approach means no compromises. Instead of fitting a project to an existing product, ADEN fits the product to the project, optimizing wire profile, slot width, support rod spacing, material grade, and screen geometry for each specific application.
What industries does ADEN serve?
ADEN serves five primary sectors -- water and wastewater treatment, food and beverage processing, oil/gas/petrochemical, mining and mineral processing, and pulp and paper -- plus additional markets including architectural screening, chemical processing, environmental monitoring wells, irrigation, and geothermal energy.
Water and wastewater applications include intake screens, rotary drums, sieve bends, flat panels, and desalination pre-filtration using T-screens, drum screens, and flat panels. Food and beverage applications include brewery, sugar, starch, dairy, juice, and oil processing all in SS 316L using sieve bends, pressure screen baskets, and flat panels. Oil, gas, and petrochemical applications include well screens, catalyst retention, polymer filtration, and produced water treatment using Johnson-type screens and header-lateral systems. Mining and mineral processing applications include dewatering, sizing, dense media separation, and vibrating screen panels using sieve bends, flat panels, and curved panels. Pulp and paper applications include pressure screen baskets, fiber recovery, and paper machine drainage elements using cylindrical baskets and slotted screens. Additional markets include architectural screening, chemical processing, environmental monitoring wells, irrigation intake structures, and geothermal well completion.
How do I request a quotation from ADEN?
Contact ADEN by email at info@adenwedgewire.com, through the website inquiry form, or via germany@adenwedgewire.com for European inquiries. Include your application, operating environment, and approximate dimensions. You will receive a material grade recommendation, screen specification, technical drawing, delivery date, and pricing within 1 business day.
The quotation process has five steps. First, submit an inquiry via email, website form, or the European office. Second, include basics such as application info, operating environment, and approximate dimensions needed. Third, ADEN engineers assess requirements and identify any gaps in an engineering review. Fourth, complex applications may include a technical call before finalizing the specification. Fifth, receive a proposal with material grade recommendation, screen specification, technical drawing for approval, confirmed delivery date, and pricing. Response time is within 1 business day. Contact channels include info@adenwedgewire.com for general inquiries, germany@adenwedgewire.com for European inquiries, and the inquiry form on the website Contact page.
Have a Technical Question?
Our engineering team is available for application-specific guidance on screen selection, material specification, and slot sizing.
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