771700

Fuel flow control function of the 771700 valve

The main function of the 771700 is controlled shut-off and opening of the fuel path. When the electromechanism receives an electrical command, it moves the valve mechanism to the required position and changes the fuel flow condition in the pipeline. This makes the unit suitable for systems where manual access is limited or where the fuel line must be controlled from the cockpit or from an automatic system. The valve is not a simple drain or service fitting; it is an active fuel system component that participates in operational control of fuel supply.

771700 with integrated MVD4E6 electromechanism

The 771700 assembly includes the shut-off valve and the MVD4E6 electromechanism. The electromechanism provides the torque needed to move the valve element and is powered from the aircraft DC electrical system. According to the passport set, the valve and electromechanism are supplied together and have separate documentation references. This is important for procurement, because the valve body and the drive mechanism should be considered as a matched assembly unless the order specifically requests only one component. The MVD4E6 designation may also appear in supply requests as part of the full product identification.

Aircraft application of 771700 in fuel lines

The 771700 is used in aircraft and helicopter fuel systems, including applications on Mi-8 and Mi-17 family helicopters depending on the aircraft configuration. It can be installed in fuel pipelines connected with engine supply circuits, auxiliary fuel lines, or other approved sections of the onboard fuel system. Since installation may vary by aircraft version, the exact location and function must be confirmed by the aircraft parts catalog and maintenance documentation. For safe operation, the valve must match the required working medium, pressure rating, electrical supply, and installation geometry.

Operating conditions for the 771700 shut-off valve

The 771700 is designed for operation with aviation fuels and air within the temperature and pressure limits specified in its passport documentation. The assembly must remain leak-tight and mechanically reliable under vibration, temperature variation, and repeated command cycles. The condition of the valve body, sealing surfaces, electrical connector, actuator shaft, and drive mechanism should be checked before installation. Since the unit controls fuel flow, even small leakage, slow movement, electrical failure, or incorrect end-position movement can affect system serviceability and aircraft maintenance acceptance.

Identification, documentation, and supply of 771700 / MVD4E6

The product is identified by the valve designation 771700 and the electromechanism designation MVD4E6. The passport set includes the valve passport 771700 PS and documentation for the MVD4E6 electromechanism. The uploaded passport indicates the assembly was accepted by quality control and includes conservation/preservation records. When ordering, it is important to specify whether the requirement is for the complete 771700 valve with MVD4E6 electromechanism, the valve only, or the drive mechanism separately. For aviation supply, original passports and condition confirmation are essential.