NP-85-2

Hydraulic pressure generation by the NP-85-2 pump

The main function of the NP-85-2 is to generate hydraulic pressure and supply working fluid to the aircraft hydraulic network. The pump can be used in circuits that feed landing gear mechanisms, wing mechanization, control-surface actuators, hydraulic locks, distribution blocks and other consumers depending on aircraft layout. Since these systems work under high pressure, pump condition directly affects pressure stability, actuator response and safe operation of the hydraulic channel. A weak pump, internal leakage or poor inlet conditions may lead to slow operation or pressure drop.

NP-85-2 as a plunger aviation pump

The NP-85-2 is described as a plunger / piston high-pressure pump. Depending on documentation and execution, it may be classified within axial-plunger or related high-pressure aircraft pump groups. This type of construction is used where high pressure is required in a compact and accurate hydraulic unit. Since the pump contains precision plunger elements, cleanliness of the working fluid is critical. Contamination, air in the suction line, low inlet pressure, clogged filtration or unsuitable fluid may quickly increase wear and cause overheating or unstable pressure.

Installation of the NP-85-2 on aircraft engines

The NP-85-2 is installed on an aircraft accessory gearbox or engine-driven unit, depending on the aircraft or engine system. The pump receives torque mechanically through a splined drive connection. In this arrangement, correct spline condition, flange fit, sealing and alignment are important. If the drive connection is damaged or the pump is mounted incorrectly, the result may be leakage, vibration, abnormal noise or drive failure. Before installation, the shaft, flange, hydraulic ports, drain line and preservation condition should be inspected carefully.

NP-85-2 with unloading and hydraulic control equipment

In a complete hydraulic system, the NP-85-2 may work together with pump unloading units, hydraulic accumulators, filters, pressure sensors and distribution valves. Unloading units such as GA-165 type equipment, or similar system devices, can move the pump into an unloaded or low-load condition when the hydraulic system reaches its maximum pressure. Hydraulic accumulators smooth pressure pulsations and store reserve hydraulic energy. Pressure sensors provide information to cockpit indicators and onboard recording or monitoring systems. Because of this, pump operation should always be evaluated as part of the whole hydraulic circuit.

Working fluids for the NP-85-2 pump

The NP-85-2 may be associated with aircraft hydraulic oils such as AMG-10 and, in certain engine-related systems, aviation fuel grades such as T-1, T-2, T-7 or RT depending on documentation. This point should be confirmed before procurement or installation, because hydraulic-pump and fuel-system executions may differ. The working medium affects materials, sealing, lubrication, leakage limits and testing procedure. For aviation use, the correct fluid must be taken from the aircraft, engine or stand documentation rather than selected by pump family alone.

Aircraft and engine application of NP-85-2

The NP-85-2 is associated with aircraft hydraulic and engine-related systems of Soviet-designed aviation equipment. It is mentioned in connection with turbojet engine accessory installations and aircraft such as Tu-22M family platforms using NK-22 type engine systems, depending on configuration. Exact installation and function must be verified by the relevant parts catalog, engine manual or hydraulic system diagram. Since similar pumps can appear in different circuits, the designation alone is not enough to confirm interchangeability.

Supply and inspection of NP-85-2

For procurement or replacement, the full designation NP-85-2 should be used. Units of this type are often supplied from storage, including preserved stock in factory conservation packaging. Before installation, the pump should be checked for housing condition, shaft and spline wear, flange face, fitting threads, cleanliness, corrosion, preservation state, drain port condition and documentation. For aviation use, bench testing is strongly recommended. The pump should be checked for pressure, delivery, leakage, temperature behavior and stable operation with the specified working medium.