Coalescing Separator Elements – Deep Dehydration, Fuel Protection

1. Product Overview

In the petrochemical and aviation fuel industries, strict purity control standards are 

mandatory for liquid media such as gasoline, diesel, light hydrocarbon solvents, 

and aviation jet fuel. During crude oil refining, pipeline transportation, tank storage,

 and aircraft refueling, external rainwater, condensed water, underground seepage,

 and process-emulsified water continuously mix into the fuel—forming free water, 

dissolved water, and surfactant-wrapped micro-emulsified droplets ranging from 0.1 μm to 

10 μm.

Left untreated, water contamination can cause:

· Corrosion of fuel tanks, pipelines, and aircraft engine fuel nozzles

· Blockage of precision metering valves

· Degradation of fuel anti-icing and anti-rust additives

· Abnormal aero-engine combustion and potential flameout during flight

Coalescing separation filter elements are the only standardized core consumables for

 deep oil-water separation in petrochemical and aviation applications.

2. Dual-Cartridge System – Complete Matching Structure

The complete filter separator vessel is equipped with two independent functional filter 

elements working in series:

Stage Component Function

First Stage Coalescing Cartridge Breaks emulsions, captures submicron water droplets,

 aggregates them into large droplets (>200 μm)

Second Stage Separation Cartridge Blocks re-entrainment of coalesced water droplets

All dimensional tolerances, bonding processes, and sealing configurations comply 

with EI 1581 Category C aviation grade standards, ensuring 1:1 interchangeability with

 imported mainstream coalescing elements.

3. Coalescing Cartridge (First Stage – Core Demulsification Component)

Flow Direction: Inside → Outside

Five-layer integrated composite structure:

Layer Material Specification Function

Inner Support Tube Epoxy-coated carbon steel or 304 stainless steel mesh Wall 

thickness 1.2–1.5 mm, aperture 4 mm, withstands ΔP ≤ 0.15 MPa Prevents inward collapse 

and bypass leakage

Fine Core Coalescence Layer Ultra-fine borosilicate glass fiber (0.7–1.2 μm diameter), 

hydrophilic modification Pore size 0.8–3 μm Captures 0.1–3 μm emulsified droplets; 

breaks surfactant film; promotes droplet coalescence

Gradient Transition Buffer Layer Mixed fiber (1–3 μm + 3–5 μm) Gradient pore transition

 Balances flow resistance and dirt-holding capacity; slows ΔP rise

Outer Pre-filter Protection Layer Coarse glass fiber (3–5 μm diameter) High void ratio,

 large dirt-holding capacity Captures rust, catalyst powder, wear debris >10 μm; protects

 inner fine fiber layer

Outer Flow Guide Wrapping Polyester non-woven fabric Uniform flow distribution Prevents

 local high-speed scouring of media surface

Additional features:

· End caps: Molded reinforced polyamide or epoxy steel plate

· Adhesive: High oil-resistant, high-temperature epoxy

· Seals: NBR/FKM elastomer rings to eliminate internal leakage

· Standard sizes: 6″ OD, lengths 11/14/22/28/33/44/56″; 4″ small-diameter models also

 available

4. Separation Cartridge (Second Stage – Anti-Re-Entrainment Barrier)

Flow Direction: Outside → Inside

Wettability: Opposite to coalescing media (super-hydrophobic / oleophilic)

Component Material Function

Support Skeleton Lightweight aluminum perforated tube Low flow resistance,

 corrosion-resistant to hydrocarbon fuel

Core Separation Media Polyester substrate + expanded PTFE microporous film Water 

contact angle >110°; blocks coalesced water droplets; allows clean fuel to pass freely

Mechanism: Coalesced water droplets are blocked on the outer surface, slide down by 

gravity into the bottom settling water tank—eliminating secondary emulsification caused 

by high-velocity fuel re-entrainment.

5. Product Performance Characteristics

Feature Description

Deep Dehydration Capability Multi-layer gradient glass fiber media with hydrophilic-oleophilic 

surface modification breaks stable oil-water emulsions

High Efficiency Outlet residual free water: ≤5 ppm (aviation fuel), ≤15 ppm 

(petrochemical fuel)

Dual-Stage Integrated System Coalescing + separation cartridges form a complete two-stage 

purification solution

Industry Standard Compliance Fully complies with EI 1581 (revised from API RP 1581), 

GJB610, and GB/T 39208

1:1 Interchangeability Dimensional, sealing, and performance matching with imported 

mainstream models

Anti-Surfactant Formulation Aviation-grade media includes anti-surfactant additives for 

high-emulsifier jet fuel

6. Application Scenarios

Industry Application

Petrochemical Refining Deep dehydration of refined oil products

Oil Depots Fuel storage and transfer water removal

Airport Hydrant Systems Aviation fuel dispensing dehydration

Mobile Refuelers On-site refueling water separation

Aviation Maintenance Fuel purity assurance for aircraft

7. Technical Performance Specifications

Parameter Specification

Filtration Media Multi-layer gradient borosilicate glass fiber (coalescing) + PTFE-coated 

polyester (separation)

Water Droplet Removal Range 0.1 μm – 10 μm (emulsified micro-droplets)

Coalesced Droplet Size 200 μm

Outlet Free Water Content ≤5 ppm (aviation) / ≤15 ppm (petrochemical)

Maximum Working Differential Pressure 0.15 MPa (coalescing cartridge)

Interchangeability Standard EI 1581 Category C

Compliance Standards EI 1581, GJB610, GB/T 39208

8. Maintenance & Operational Guidelines

Step Action

Pre-Installation Verify cartridge dimensions and seal condition

Installation Ensure proper seating of both coalescing and separation cartridges

Commissioning Slowly pressurize; check for leaks; monitor differential pressure

Monitoring Track ΔP rise and outlet water content regularly

Replacement Trigger Replace when differential pressure reaches alarm value or outlet 

water content exceeds limits

Disposal Follow local regulations for spent cartridge disposal

9. Summary – Why Choose Our Coalescing Separation Filter Elements?

· Equivalent Performance – EI 1581-compliant, identical efficiency to original models

· Proven Reliability – Multi-layer gradient media with anti-surfactant protection

· Cost-Effective Supply – Competitive pricing, shorter lead times, consistent quality

· Full Range Availability – 6″ and 4″ sizes, multiple lengths to fit all standard housings

· Technical Support – Expert guidance for selection, installation, and troubleshooting

Contact Us

We supply a comprehensive range of coalescing and separation filter elements for 

petrochemical and aviation fuel applications. Sample testing and bulk order support are 

readily available.

Contact our technical team for detailed datasheets, cross-reference verification, 

and tailored quotations.

Need more information on fuel dehydration solutions?

Please contact our engineers today for expert assistance.