MDI Aerovalve F391-53S Flush Fuel Drain Valve is an FAA-PMA approved aircraft fuel system component designed to provide safe, reliable, and convenient draining of fuel during pre-flight inspections and routine maintenance. Featuring a 7/16"-20 TPI threaded connection, this flush-mounted valve installs nearly flush with the aircraft surface, reducing the risk of accidental damage while maintaining a clean aerodynamic profile.

The valve enables technicians and pilots to obtain fuel samples for inspection of water, sediment, or other contaminants before flight. Its internal spring-loaded mechanism remains securely closed during normal operation and opens only when actuated with a compatible fuel sampler cup or probe, minimizing unintended fuel loss and improving safety during servicing.

Manufactured for dependable operation in aviation fuel systems, the F391-53S is widely used as original equipment and replacement hardware on compatible aircraft. Its durable construction provides excellent resistance to aviation fuels and repeated maintenance cycles, making it a reliable choice for long-term service.

Routine inspection of the valve for smooth operation, sealing performance, and evidence of leakage is recommended during scheduled maintenance to help preserve fuel system integrity and ensure continued airworthiness.

Key Features

- Part Number: F391-53S
- Manufacturer: MDI Aerovalve
- Component: Flush Fuel Drain Valve
- Thread Size: 7/16"-20 TPI
- Mounting Style: Flush-mounted design
- Approval: FAA-PMA approved replacement part
- Spring-loaded valve opens only with a compatible fuel sampler cup or probe
- Designed for fuel sampling, contamination inspection, and controlled fuel draining
- Durable construction for reliable operation and long service life in aircraft fuel systems