771300

Operating principle of 771300

The two-way plate-type valve is moved by an MPK-13A-5 electric mechanism. A thermal valve is incorporated in the assembly, while limit-switch circuits stop the drive and provide position indication. Reliable operation depends on clean working fluid, the moving element, seat, springs and seals. Contamination, reversed connections or an unsuitable pressure can prevent the intended response.

Role in the aircraft system

Il-76 fuel system. Technical documentation places 771300 valves at several supply, fire-isolation, crossfeed and auxiliary-power-unit lines; tank installations mount the valve body inside the tank and the mechanism outside the rear spar wall. The valve works with pipelines, a pressure source, downstream equipment and the control elements of its circuit. These products are functionally related but must not be described as interchangeable merely because they operate in the same system.

Installation and maintenance checks

Before installation, verify the nameplate, ports, flow direction, internal cleanliness and seal condition. Working pressure, temperature, fluid and the prescribed functional test must come from the passport and maintenance documentation. Adjustment without approved instructions is not permitted. Incoming-inspection results should remain with the product records.

Identifying 771300 for ordering

Confirm designation 771300, the MPK-13A-5 mechanism execution, connector, thermal-valve arrangement and installation position. Different fuel-line positions are related but not interchangeable without the aircraft documentation. Other related products are listed in the valves category. An enquiry should state the complete designation, execution, condition, delivery set and required supporting documents.