LEFILTER Replacement Coalescer Filter Element for FAUDI Model A.1-559

Product Overview

The FAUDI A.1-559 is one of the most widely recognized model codes in the coalescer filtration industry, frequently specified for aviation fuel handling systems, petrochemical refineries, and bulk storage terminal operations. LEFILTER’s replacement version is manufactured to exacting standards, ensuring seamless interchangeability with the original FAUDI element while incorporating upgraded material formulations that enhance contaminant holding capacity and coalescing efficiency.

This replacement coalescer filter element is constructed using high-purity borosilicate glass fiber media with a progressive density gradient. The outer layers capture larger particles and debris, while the inner hydrophilic fiber network targets micron-sized water droplets and fine aerosols. Through the principle of coalescence, these tiny dispersed droplets collide and merge into larger droplets that separate by gravity, allowing purified fluid to continue downstream while water collects in the sump for removal.

Filtration Mechanism & Coalescence Principle

The LEFILTER FAUDI A.1-559 replacement element employs a dual-stage purification process that ensures comprehensive fluid cleaning.

Stage 1 – Mechanical Filtration:
As the contaminated fluid passes from the outside to the inside of the element, the outer coarse fiber layer traps large solid particles, rust, scale, and other mechanical impurities. This pre-filtration step protects the inner precision media from premature clogging and extends the overall service life of the element.

Stage 2 – Water Coalescence:
The fluid then enters the hydrophilic borosilicate glass fiber matrix, which features a gradient pore structure. This media is specifically treated to exhibit strong water-attracting (hydrophilic) properties. As tiny emulsified water droplets pass through the dense fiber network, they are captured and held by the fibers. Continuous fluid flow causes these captured droplets to collide with one another, gradually merging into larger droplets through a process known as coalescence. Once the droplets reach a critical size, their weight overcomes the fluid’s suspension force, causing them to fall by gravity into the collection sump at the bottom of the filter housing.

This coalescing mechanism is highly efficient for removing both free water and emulsified water that cannot be separated by conventional gravity separators alone. The purified fuel or hydrocarbon liquid exits the element with significantly reduced water content and particulate contamination, protecting downstream equipment such as pumps, meters, control valves, and combustion systems from corrosion, erosion, and operational failures.

Structural & Material Advantages

1. Aviation-Grade Gradient Glass Fiber Media

The core filtration layer is composed of high-purity borosilicate glass fibers arranged in a progressive density gradient. This design ensures that larger contaminants are trapped in the outer layers, while the finer inner layers capture sub-micron particles and micro-water droplets. The media exhibits excellent chemical inertness, making it compatible with a wide range of hydrocarbons including aviation kerosene, Jet A/A-1, diesel, gasoline, and various light petroleum solvents. Its super-hydrophilic surface treatment enhances water capture efficiency, achieving consistent coalescing performance throughout the element’s operational life.

2. High-Strength Reinforced End Caps

Both end caps are precision-molded from glass fiber reinforced polyamide, a material chosen for its dimensional stability, impact resistance, and compatibility with hydrocarbon fluids. The end caps are manufactured to match the exact interface dimensions of the original FAUDI A.1-559, ensuring a drop-in fit without requiring any modification to the existing filter housing or piping configuration.

3. NBR Sealing System

The element is equipped with high-quality NBR (Buna-N) O-rings and gaskets that provide reliable zero-leakage sealing even under fluctuating pressure and temperature conditions. NBR is selected for its excellent resistance to petroleum-based fluids, ozone, and aging, ensuring long-term sealing integrity and preventing bypass flow that would compromise filtration efficiency.

4. Epoxy-Coated Steel Support Core

A robust central support tube made of epoxy-coated carbon steel provides radial strength to the filter media, preventing collapse or deformation under high differential pressure conditions. The epoxy coating offers additional corrosion resistance, ensuring structural integrity even in moist or chemically aggressive environments. All component joints are sealed using hot-melt integration technology, eliminating the risk of adhesive degradation or dissolution that could introduce secondary contamination into the fluid stream.

Application Scenarios

The LEFILTER FAUDI A.1-559 replacement coalescer element is specifically engineered for applications where high-purity fuel or hydrocarbon liquids are required. Typical installations include:

• Aviation Fuel Depots & Hydrant Systems: Removing free water and fine particulates from jet fuel to meet ASTM D1655 and DEF STAN 91-91 quality specifications, protecting aircraft engines and fuel system components from water-induced corrosion and icing risks.

• Petroleum Refineries & Processing Plants: Polishing finished products such as gasoline, diesel, and kerosene before storage or shipment, ensuring product clarity and stability.

• Bulk Fuel Storage Terminals: Protecting transfer pumps, flow meters, and pipeline networks from abrasive particles and water slugs that can cause equipment wear, measurement errors, and pipeline corrosion.

• Industrial Light Hydrocarbon Systems: Purifying solvents, feedstocks, and intermediate streams in chemical and petrochemical manufacturing processes.

• Marine & Power Generation: Treating fuel oil and turbine oils to extend equipment life and reduce maintenance downtime.

Quality Assurance & Industry Compliance

Every LEFILTER FAUDI A.1-559 coalescer element undergoes stringent factory testing to verify its performance, integrity, and interchangeability. The manufacturing process is ISO 9001 certified, and the finished products are tested in accordance with internationally recognized filtration standards:

• ISO 2941 – Collapse and burst resistance verification

• ISO 2942 – Fabrication integrity and bubble-point testing

• ISO 16889 – Multi-pass performance testing for filtration efficiency

• EI 1581 – Aviation-specific requirements for water separation and particulate removal

These certifications ensure that LEFILTER replacement elements not only match but in some cases exceed the performance characteristics of original OEM products, providing industrial users with a reliable, high-value alternative.

Detailed Technical Specifications