Filter Separator for Fluid Pressure, Aviation & Diesel Fuel - 403M | Cla-Val

Cla-Val 403M Fuel-Water Filter Separator

The Cla-Val 403M is a pressure-type filter separator designed for aviation fuels and diesel. Product documentation describes it as a Filter Separator for Fluid Pressure, Aviation and Diesel Fuel. The Cla-Val marine quick reference lists it under fuel-water filter/separators for Av-Gas, JP-5, and Diesel Fuel.

Functional Role

Installed in fuel transfer or distribution lines where removal of solids and separation of free water is required upstream of downstream equipment. Typical locations include fuel transfer skids, aviation fuel service lines, diesel fuel systems, and marine refueling systems.

Standards and Configuration

The quick reference specifies the 403M series as compliant with MIL-F-15618 (SHIPS) for filter separators (fluid pressure, aviation, and diesel fuel), Class 1 with automatic drain & fuel shutoff controls. Flanged connections per MIL-F-20042 Class 150 / Class 250 are standard; union connections per MIL-F1183 are available for specific configurations or accessories.

Selection Criteria

• Fuel type: Av-Gas, JP-5, or diesel
• Flow rate and allowable pressure drop
• Operating pressure vs. Class 150 or Class 250
• Requirement for automatic drain and fuel shutoff controls
• Flange or union connection type
• Material compatibility with fuel and additives
• Access for element replacement and water drainage

Maintenance

Operation should be monitored for differential pressure, coalescer/separator element condition, water accumulation in the sump, flange tightness, and automatic drain function. Increased differential pressure indicates element saturation or fouling.

FAQ

Is this a standard fuel filter?
No. It is a fuel-water separator for pressure applications.

Which fuels are supported?
Av-Gas, JP-5, and diesel fuel.

What must be verified before procurement?
Size, flange class, flow rate, operating pressure, filter elements, and required drain/shutoff automation.