Overview
Anhui Xinfulong's FEP Lined Check Valves are engineered for reliable, automatic backflow prevention in corrosive and high-purity fluid handling systems. Also known as non-return valves, our FEP lined check valves allow the medium to flow in only one direction while automatically preventing flow in the opposite direction. The valve disc opens under the pressure of forward fluid flow and closes rapidly when flow reverses, cutting off the passage without requiring any external power.
FEP (Fluorinated Ethylene Propylene) — also designated as F46 — is a melt-processable fluoropolymer renowned for its exceptional chemical resistance, broad temperature range, and non-stick surface properties-. When fully lining the valve body, disc, and sealing surfaces, FEP provides complete isolation of the metal valve structure from the process medium, delivering corrosion resistance that far exceeds that of expensive alloy valves at a fraction of the cost.
Available in multiple configurations — swing type, lift type, and wafer dual-plate type — our FEP lined check valves are widely deployed in semiconductor wet processing, wet electronic chemicals, pharmaceutical manufacturing, chemical processing, and new energy applications where backflow protection and corrosion resistance are mission-critical.
Key Features
Superior Corrosion Resistance
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Full FEP lining on all wetted parts — valve body interior, disc, and sealing surfaces — completely isolates the metal body from the process medium
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Chemically inert to virtually all corrosive media, including hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, aqua regia, various organic acids, strong alkalis, oxidants, and organic solvents
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Outperforms expensive alloys (Hastelloy, titanium, tantalum) in aggressive chemical environments while significantly reducing equipment costs
Reliable Automatic Operation
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Self-actuated — no external power, air supply, or control signals required
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Valve disc opens and closes automatically based on the direction of medium flow
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Spring-assisted closure (where applicable) ensures rapid response and reliable sealing even in low-pressure areas
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Prevents water hammer damage through fast, controlled closure
Superior Sealing Performance
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Both disc and seat sealing surfaces are lined with FEP fluoroplastic layers
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Unique spring design provides continuous sealing pressure, ensuring reliable sealing even in low-pressure differential conditions
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Bubble-tight shut-off prevents reverse flow and contamination of upstream processes
Full Bore / Low Flow Resistance Design
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Full-port straight-through design minimizes pressure drop and medium residue
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Reduces crystallization and blockage common in chemical processing
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High flow coefficient (Cv) values for maximum throughput efficiency
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Short disc travel reduces fluid resistance and improves flow efficiency
Versatile Configurations
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Swing Type (Flap Type) — Disc rotates around a hinge pin; simple, robust design suitable for horizontal pipeline installation
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Lift Type (Straight Type) — Disc slides along the vertical centerline; excellent sealing performance, suitable for horizontal pipelines
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Wafer Dual-Plate Type — Short, compact double-disc design; minimizes fluid resistance and improves opening response speed
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Ball Check Type — Solid PTFE ball rolls into the seat by gravity, providing reliable sealing
Easy Maintenance & Long Service Life
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Simple, robust mechanics with minimal moving parts
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Non-stick FEP surface prevents scale and sludge buildup
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Low opening pressure — some designs require as little as 0.07 bar (1 psi) to unseat
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Anti-blow out stem design prevents accidental ejection under pressure
Technical Specifications
Applications
Our FEP Lined Check Valves are widely deployed across industries requiring corrosion-resistant, reliable backflow protection:
Semiconductor Manufacturing
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High-purity chemical distribution systems for wet etching and wafer cleaning
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Ultra-pure water (UPW) systems
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Handling of hydrofluoric acid, sulfuric acid, nitric acid, and high-purity solvents
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Wet process equipment and chemical mechanical planarization (CMP) slurry lines
Wet Electronic Chemicals
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Transfer and control of high-purity acids, etchants, and solvents
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Chemical blending and distribution systems
- High-purity reagent feed lines
Chemical & Petrochemical Processing
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Handling of strong acids (sulfuric, hydrochloric, nitric, hydrofluoric)
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Caustic soda and alkaline solutions
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Organic solvents and aggressive media
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Chlor-alkali processes and pickling lines
Pharmaceutical & Biotech
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High-purity fluid transfer with zero contamination risk
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Solvent and reagent delivery systems
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FDA-compliant processing lines
New Energy
Water & Wastewater Treatment
Why Choose Xinfulong FEP Lined Check Valves?
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Superior Corrosion Resistance — FEP lining provides chemical resistance superior to expensive alloys and far outlasts standard metal valves in corrosive service
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FEP vs. PTFE Advantage — FEP liners are inherently less porous than PTFE, offering better permeation resistance in demanding applications
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Complete Isolation — Full FEP lining on all wetted parts — body, disc, seat, and spring — ensures zero metal contact with the process medium
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Automatic, Maintenance-Free Operation — No external power or control signals required; self-actuated based on flow direction
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Cleanroom Manufacturing — Critical production processes carried out in Class 1000/10,000 cleanrooms, ensuring the highest levels of purity
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Industry-Leading Expertise — Backed by decades of fluoropolymer processing experience and R&D collaboration with Japanese and Korean experts
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Proven Global Track Record — Trusted by clients across Europe, Japan, Korea, Taiwan (China), and beyond
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Comprehensive Quality Assurance — ISO 9001, ISO 14001, ISO 45001 certified with full in-house testing capabilities including electrospark testing of lining layers
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End-to-End Service — From custom design and material selection to manufacturing, testing, and after-sales support
Customization Options
We offer fully customizable FEP lined check valves to meet your specific requirements:
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Valve sizes from DN15 to DN500
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Multiple configurations: swing type, lift type, wafer dual-plate type, ball check type
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Body materials: ductile iron, carbon steel, or stainless steel
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Connection types: flanged (ANSI, DIN, JIS, GB), wafer, or lug
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Spring-assisted or gravity-only closure
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Special trim materials and configurations
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Custom pressure and temperature ratings
