Coalescing Separation Filter: The Ultimate System for Pure, Dry Compressed Air & Gas
A Coalescing Separation Filter is an integrated filtration system—comprising a filter housing (vessel) and a replaceable coalescing filter cartridge—designed to remove liquid aerosols, oil mist, water, and fine solid contaminants from compressed air and other gas streams. It is the essential solution for achieving the highest levels of air/gas purity, protecting sensitive equipment, and ensuring product quality. Lefilter provides high-performance, reliable Coalescing Separation Filter Systems and components for a wide range of critical industrial applications.
How a Coalescing Separation Filter System Works
The system operates on the principle of coalescence, effectively turning tiny, problematic aerosols into easily removable liquids. The process unfolds in two stages within a single, integrated unit:
Filtration & Coalescing Stage: Contaminated gas enters the filter housing and flows from the outside into the coalescing filter cartridge. This specialized cartridge contains a dense matrix of fine borosilicate glass microfibers. As the gas passes through, sub-micron oil and water aerosols collide with the fibers, coalesce into larger, heavier droplets, and solid particles are trapped.
Separation & Drainage Stage: The clean gas flows toward the center of the cartridge and exits. The enlarged liquid droplets, now separated from the gas stream, are shed onto the cartridge's inner surface. They then drain by gravity into the filter housing’s sump, where they are automatically or manually expelled via a drain valve. This two-stage, in-one process ensures exceptionally dry and clean output.
System Components & Key Advantages
Our Coalescing Separation Filters are engineered for maximum performance, durability, and ease of maintenance, offering distinct advantages:
Superior Filtration Efficiency: Achieve >99.99%+ removal of oil and water aerosols down to 0.01 micron, delivering clean air that meets or exceeds ISO 8573-1 Class 1 or Class 0 standards.
Integrated, Compact Design: A complete, ready-to-install system that combines coalescing and separation in one robust housing, saving space and simplifying your piping layout.
Low, Stable Pressure Drop: Optimized flow paths and high-quality filter media minimize energy consumption and extend the service life of the filter cartridge.
High Dirt-Holding Capacity: The coalescing cartridge is designed to hold a significant volume of liquid and particulate contaminants, reducing change-out frequency and lowering total cost of ownership.
Automatic Operation: Available with automatic float drains or electronic drain valves to reliably expel collected liquids without manual intervention, ensuring consistent system performance.
Reliable Construction: Filter housings are made from corrosion-resistant materials (carbon steel with epoxy coating, stainless steel) and are rated for high working pressures, suitable for demanding industrial environments.
Technical Specifications & Selection Guide
Parameter | Specification / Guideline |
|---|
Primary Function | Removal of Liquid Aerosols (Oil, Water, Chemicals) & Fine Particulates from Gases |
Typical Filtration Grade | 0.01 µm for liquids, 0.3 µm for solids (efficiency >99.99%) |
Housing Connection Sizes | 1/2" to 2" NPT / BSP (Common), Flanged connections for high-flow applications |
Standard Housing Material | Carbon Steel (Epoxy Coated), 304 or 316 Stainless Steel |
Maximum Operating Pressure | 150 PSIG, 300 PSIG, 450 PSIG (Standard ratings. Custom high-P available) |
Operating Temperature | Standard: -20°F to 180°F (-29°C to 82°C) |
Drain Options | Manual Ball Valve, Float Drain, Solenoid-Operated Zero-Loss Drain |
Element Type | High-Efficiency Coalescing Cartridge (Replaceable) |
Element Connections | Double Open End (DOE), Single Open End (SP/TC) to match housing |
Critical Industry Applications
A Coalescing Separation Filter is indispensable in any application where clean, dry, oil-free air or gas is non-negotiable:
Instrument & Plant Air: Protects sensitive pneumatic instruments, control valves, and cylinders from oil and water contamination, preventing failures and downtime.
Critical Manufacturing: Essential for laser cutting (protecting lenses), CNC machining (air bearings/spindles), painting, and powder coating to ensure product quality.
Food & Beverage & Pharmaceutical: Provides oil-free air for product contact, packaging, and processes to meet strict health, safety, and quality regulations (FDA, cGMP).
Natural Gas Processing: Removes lube oil aerosols and particulates from pipeline gas, protecting compressors, turbines, and metering skids.
Aviation & Aerospace: Supplies ultra-dry, oil-free air for ground support equipment and for testing aircraft components.
Frequently Asked Questions (FAQ)
Q: What is the difference between a Coalescing Separation Filter and a standard particulate filter?
A: A particulate filter only removes solids. A Coalescing Separation Filter is designed to remove both solid particles and liquid aerosols (oil/water mist). It uses a special cartridge to coalesce the tiny liquid droplets so they can be separated and drained away, which a particulate filter cannot do.
Q: Where should I install a coalescing filter in my compressed air system?
A: Ideally, install it downstream of the air compressor and aftercooler/receiver, but before any air dryer (refrigerated or desiccant) and point-of-use equipment. This protects the dryer and all downstream tools/instruments.
Q: How do I maintain a Coalescing Separation Filter?
A: Maintenance involves two main actions: 1) Regularly check and service the drain valve to ensure liquids are being expelled automatically, and 2) Replace the coalescing filter cartridge when the differential pressure (ΔP) across the housing reaches 7-8 PSID or as per the manufacturer's schedule.
Q: Can I use any brand of replacement cartridge in your filter housing?
A: Our housings are designed for optimal performance with our high-efficiency cartridges. We also offer models compatible with industry-standard cartridges from major OEMs (Pall, Donaldson, Parker, etc.). Please consult with us to ensure correct cartridge selection for your specific housing model.
Q: Do I need a pre-filter before the coalescing filter?
A: In most cases, yes. Installing a general-purpose particulate filter (e.g., a 1 µm or 5 µm filter) upstream protects the more expensive coalescing cartridge by removing bulk solids and extending its service life. This is considered a best practice.
