GA-121M-3

Operating principle of GA-121M-3

System pressure acts on the internal sensing and control elements. At the calibrated condition the unit changes the pump unloading path, reducing unnecessary pump load; the exact pressure sequence must be taken from the engine manual. 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

Engine pump-control systems. Aviation parts catalogues associate GA-121M-3 with AI-20, NK-8-4, D-30KU and D-30KP engine families; the exact installation requires the engine modification documentation. 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 GA-121M-3 for ordering

Verify the complete GA-121M-3 nameplate, pump type, engine modification, pressure setting and port assignment. Do not substitute GA-121M or another suffix by appearance. Other related products are listed in the valves category. An enquiry should state the complete designation, execution, condition, delivery set and required supporting documents.