NP-25-5

NP-25-5 as an aircraft hydraulic pump

The NP-25-5 is an aircraft high-pressure plunger hydraulic pump with regulated delivery. It is designed to supply working fluid to onboard hydraulic systems of aircraft and to hydraulic circuits of specialized equipment. The pump converts mechanical rotation from the drive shaft into high-pressure hydraulic flow. In aviation use, the NP-25-5 is installed on the aircraft engine accessory gearbox and works as one of the pressure sources for hydraulic consumers that require stable and controlled fluid supply.

Hydraulic pressure generation by NP-25-5

The NP-25-5 operates at a working pressure of 25 MPa / 250 kgf/cm². Its nominal delivery is 17 L/min at a nominal shaft speed of 2200 rpm. The pump is designed to work with AMG-10 hydraulic fluid and supply pressure to aircraft hydraulic system lines. Since the pump is used in high-pressure circuits, its condition directly affects the operation of hydraulic actuators, control units and mechanisms connected to the system. Stable suction conditions and clean hydraulic fluid are essential for correct operation.

Plunger operating principle of NP-25-5

The NP-25-5 works through reciprocating movement of plungers. When a plunger moves in one direction, it creates low pressure in the cylinder cavity and opens the suction valve, allowing hydraulic fluid to enter. During the return stroke, the fluid is compressed and forced through the discharge valve into the high-pressure line. This operating principle allows the pump to create high pressure in a compact body. Wear of plungers, valves or sealing elements can quickly reduce pressure and delivery stability.

Installation of NP-25-5 on aircraft engines

In aircraft use, the NP-25-5 is mounted on the aircraft engine accessory gearbox. On Il-76 aircraft, it is associated with D-30KP engines used on Il-76M and Il-76MD modifications. The pump is installed by a mechanical drive connection and receives rotation from the engine accessory gearbox. During installation or replacement, the mounting flange, shaft direction, drive interface, sealing surfaces and hydraulic lines must be checked. The direction of rotation is especially important when selecting the correct version.

NP-25-5 in Il-76 hydraulic systems

The NP-25-5 is used as part of the onboard equipment of Il-76 heavy military transport aircraft. In this role, it supplies pressure to hydraulic system units and supports operation of aircraft hydraulic consumers. The exact consumers depend on the aircraft hydraulic system configuration, but such pumps are generally used to feed hydraulic actuators, control mechanisms and power circuits. For aircraft installation, the pump must be checked against the aircraft maintenance documentation, engine configuration and approved parts catalog.

NP-25-5 and NP-25-5L versions

The pump may appear in documentation and on nameplates as NP-25-5, NP25-5, NP-25-5L or NP25-5L. The “L” suffix usually indicates left-hand shaft rotation. This distinction matters because pumps with different rotation directions are not selected only by physical similarity. If the wrong rotation version is installed, the pump may not provide the required delivery or may be damaged. For procurement, the full designation and required shaft rotation should be confirmed before shipment.

Use of NP-25-5 in specialized ground equipment

Besides aviation, the NP-25-5 and especially the NP-25-5L version may be used in specialized ground machinery. It is found in hydraulic systems of drilling-crane machines and heavy special-purpose equipment, including installations based on Ural or KamAZ truck chassis. In these applications, the pump is valued for its high working pressure and compact design. For non-aircraft use, mounting, shaft rotation, working fluid, filtration and operating mode should still be verified before installation.

Supply and documentation for NP-25-5

For supply, the pump should be requested by its full designation: NP-25-5 / НП-25-5, or NP-25-5L / НП-25-5Л if the left-hand rotation version is required. For aircraft use, passport and aviation technical documentation are important. Before installation, the pump should be checked for pressure, delivery, suction condition, leakage, shaft seal condition, flange condition and drive compatibility. Units supplied from storage or after repair should be accepted only after documentation and performance checks.

Product Type: High-pressure plunger hydraulic pump with regulated delivery
Designation: NP-25-5
Alternative Designations: НП-25-5; NP-25-5; НП25-5; NP25-5
Related Version: NP-25-5L / НП-25-5Л / НП25-5Л, left-hand rotation version
Function: Supply of hydraulic working fluid under pressure to aircraft or special equipment hydraulic systems
Application / Where Used: Aircraft hydraulic systems; specialized ground hydraulic equipment
System / Installation Area: Aircraft engine accessory gearbox / hydraulic pressure supply system
Compatible Aircraft / Equipment: Il-76, Il-76M, Il-76MD with D-30KP engines according to supplied data; drilling-crane machines and special hydraulic equipment depending on configuration
Pump Type: High-pressure plunger / piston hydraulic pump
Delivery Type: Regulated delivery
Working Pressure: 25 MPa / 250 kgf/cm²
Flow Rate: 17 L/min
Nominal Shaft Speed: 2200 rpm
Working Fluid: AMG-10 hydraulic oil
Hydraulic Fluid Temperature Range: −40 to +80 °C
Suction Pressure: Not less than 200–600 mmHg according to supplied data
Operating Principle: Reciprocating plunger movement with suction and discharge valves
Mounting Type: Mechanical installation on aircraft engine accessory gearbox
Associated Engine: D-30KP, according to supplied Il-76 application data
Approximate Overall Dimensions: Diameter approx. 140–160 mm; length approx. 250–290 mm
Weight: 4.7 kg
NP-25-5L Weight Reference: 5.5 kg
Inspection / Testing: Delivery check, working pressure check, suction condition check, leakage check, shaft rotation direction check, flange and seal inspection

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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.