Fueling and Defueling Valves

Marine aviation fuel fueling and defueling valves are used in shipboard aviation fuel systems to control flow, pressure, and hydraulic surge during transfer of AVGAS or jet fuel. Their application includes aircraft fueling stations on naval platforms such as CVN, LHA, LHD, LPD, and LPH vessels, where the same valve arrangement must support both fueling and defueling duty.

This category includes the Cla-Val 302M Automatic Fueling and Defueling Valve. It is a 2-1/2 in flanged valve manufactured to MIL-F-20042 Class 250, with available construction in valve bronze and Monel internal trim for compliance with naval material requirements. Its function is to maintain downstream pressure and limit surge during fueling service, while the three-port configuration provides separate flow paths for fueling and defueling operation.

The 302M is used with the Cla-Val 345GF semi dry-break disconnect assembly. The dry-break arrangement retains fuel in the hose or pantograph after disconnection, and the continuity switch provides a signal for pump control and solenoid actuation on the 302M. The valve control circuit includes a 3-way Hytrol main valve, pressure relief controls, pressure reducing control, solenoid control, ejector strainer, and flow control components. For this reason, the valve should be evaluated as a control assembly rather than as a simple shut-off device.

During selection and maintenance, the flange class, fuel cleanliness, pressure drop, pilot line response, strainer condition, pressure relief and reducing control settings, solenoid function, and shutoff tightness during disconnect should be verified. Contaminants, water, corrosion products, or incorrect pilot adjustment can affect fueling pressure, response time, and safe defueling operation.