Replacement Parker Velcon OS Series OS-51288 Coalescer/Separator Cartridges for Aviation & Diesel Fuels

Our Replacement Velcon OS Series Coalescer/Separator Cartridges are high-efficiency, single-piece filter elements specifically designed for removing particulate contaminants and free/emulsified water from hydrocarbon fuels.

Combining two-stage filtration into a single, compact cartridge, the OS Series delivers superior fuel purity for aviation jet fuel, avgas, and diesel applications. Built as a direct drop-in replacement, these cartridges perfectly fit standard housings including VF-61, VF-609, Racor® FBO-10 & FBO-14, as well as Facet® VFCS-21 & VFCS-22 vessels.

Featuring high-performance PTFE-coated screen separators and a robust radial sump seal, our replacement OS series ensures high flow rates, low pressure drop, and exceptional reliability even under rigorous operating conditions.

Working Principle

The cartridge operates on an Outside-to-Inside flow direction:

Particulate Filtration & Coalescing: As raw fuel flows from the outside to the inside, the coalescer layer captures solid particles (dirt, rust, pipe scale) and forces emulsified water droplets to merge into larger, heavier water drops.

Water Separation: The coalesced water droplets migrate toward the inside layer, where a hydrophobic Teflon®/PTFE coated screen separator repels the water, preventing it from passing through.

Drainage & Clean Fuel Output: The separated water drops down into the housing sump for routine daily draining. Clean, dry fuel exits the cartridge through the top nozzle into the system outlet.

Applications & Vessel Compatibility

Aviation Fueling: Jet A/A-1, Avgas handling, refuelers, hydrants, and airport fuel depots.

Diesel Fuel Filtration: Fleet refueling, industrial diesel dispensing, marine diesel systems, and backup generator fuel conditioning.

Industrial Hydrocarbon Processing: Prefiltration and water separation for light light-hydrocarbon liquids.

Compatible Filter Vessels & Housings:

Velcon / Parker: VF-61, VF-61E, VF-609

Racor®: FBO-10, FBO-14

Facet® / PECO Facet: VFCS-21, VFCS-22

Integrated Two-in-One Design: Single-piece combination of coalescer and separator simplifies replacement and lowers inventory costs.

Superior Water Removal Efficiency: Laboratory-tested to handle up to 0.2% incoming water content, delivering effluent with less than 10 ppm water.

Anti-Icing Additive Compatibility: Fully compatible with pre-mixed fuels containing DiEGME / FSII anti-icing additives.

High Dirt Holding Capacity: Premium microfiber media provides nominal 0.5 micron rating for Jet Fuel/Avgas and 5 micron rating for Diesel Fuel.

Reliable Radial Sump Seal: Ensures a positive leak-proof seal and prevents unfiltered fuel bypass.

Rugged Structural Integrity: Minimum 75 psid collapse strength ensures stable operation under differential pressure.

Wide Operating Range: Temperature rating up to 250°F (121.1°C) and continuous operation within a pH range of 5 to 9.