KP-9V

KP-9V air bleed valve in the AI-9V APU system

The KP-9V is an electropneumatic air bleed valve used in the AI-9V auxiliary power unit system. It works with compressed air from the APU compressor and controls whether part of that air is discharged to atmosphere or kept in the starting air circuit. The valve is not an air starter and does not rotate the main engine by itself. Its job is to manage compressor bleed during AI-9V operation, so the APU can run steadily before air is sent to the helicopter engine starting system.

KP-9V operation during AI-9V start and idle

During AI-9V start, idle operation, and generator mode, the KP-9V valve is open. In this position, part of the compressed air from the receiver is bled overboard. This helps the APU compressor work without surge at low and transitional operating modes. The idea is simple: while the air is not yet being used for main engine starting, the system gives the compressor a controlled outlet. If the bleed path is blocked or the valve does not open correctly, the APU may show unstable compressor operation.

Airflow change through the KP-9V valve

When the helicopter main engine start command is given, the system changes the air path. The KP-9V closes the bleed outlet, and compressed air is directed toward the air starter of the main engine. On helicopters with TV3-117 family engines, this air is used to spin the starter turbine and begin engine acceleration. The KP-9V therefore sits at an important point between the AI-9V compressor, receiver cavity, bleed outlet, and starting air line. It does not make the start sequence by itself, but without correct valve operation the air path will not be correct.

AI-9V system components around KP-9V

The KP-9V works together with the AI-9V compressor, receiver, starting air lines, air starter, electrical control circuits, and the starting automation equipment installed on the helicopter. Depending on the aircraft configuration, the start command may come through the engine starting panel and related automation circuits. The valve itself has automatic pneumatic behavior with electrical control in the system. Some descriptions mention a Venturi-type insert used for air flow limitation during bleed operation. For maintenance, the valve should be checked together with air pressure, valve movement, electrical command, leakage, and the condition of the connected air lines.

Identification and ordering checks for KP-9V

The KP-9V is used on helicopters equipped with the AI-9V auxiliary power unit, including Mi-8 / Mi-17 family helicopters and other platforms where AI-9V installation is confirmed by the aircraft documentation. Before ordering, the installed valve marking should be checked against the APU documentation, helicopter parts catalog, or maintenance records. A visually similar bleed valve may not be the correct item if the installation, air line connection, or control circuit differs. The product is also known under alternative designation КП-9В.

Product Type: Electropneumatic air bleed valve
Function: Compressor air bleed control and switching of air flow during AI-9V operation
Application / Where Used: AI-9V auxiliary power unit air bleed and starting air system
System / Installation Area: APU compressor receiver / starting air supply system
Compatible Aircraft / Equipment: Helicopters equipped with AI-9V APU, including Mi-8 / Mi-17 family helicopters, Mi-24, Ka-32 where confirmed by aircraft documentation
Working Medium: Compressed air
Associated Equipment: AI-9 / AI-9V APU, main engine air starters, starting air lines, starting automation circuits
Operating Modes: Open during AI-9V start, idle, and generator mode; closed during air bleed for main engine start
Main Components: Air valve assembly; electropneumatic control elements; possible Venturi-type flow limiting insert depending on version
Technical Documentation: AI-9V APU documentation / helicopter maintenance documentation

All shipments are carried out from our international warehouse in Dubai (UAE), as well as from our partners’ remote warehouses.

In Stock — items available in stock at the Dubai warehouse are dispatched within 5–10 business days after receiving 100% prepayment.

Remote Stock — items available at our partners’ remote warehouses are supplied within an average of 30–45 business days after receiving 100% prepayment.

Pre-Order — made-to-order products are manufactured and delivered within an average of 45–60 business days. Payment terms: 50% advance payment to start production, with the remaining 50% paid before dispatch from the Dubai warehouse after full readiness for shipment.

Returns & Changes (Restocking Fee)
For selected items, a RESTOCKING FEE of 10% may apply in case of return, order cancellation, or changes to the order specifications. This condition applies only to certain products and is confirmed at the order approval stage.

Warranty
All products are covered by a standard 6-month warranty.
Extended warranty is available upon request and is agreed individually; it may affect the final product price.