2259T

Operating principle of 2259T

When the solenoid is energized, its plunger moves a double-acting valve between the seats and changes the connection of ports I, II and III. Depending on the installation, this transfers the control signal to the standby regulator or opens the depressurization control line. 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

Aircraft cabin-pressure regulation system. Yak-42 documentation shows 2259T valves between 2077AT regulators and 4870T discharge-valve anti-pulsators, as well as in cabin-depressurization lines. 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 2259T for ordering

Verify the Cyrillic source marking 2259Т, electrical connector, port assignment and installation purpose. A valve used for regulator switching and one used for depressurization can share the same designation but different piping. Other related products are listed in the valves category. An enquiry should state the complete designation, execution, condition, delivery set and required supporting documents.