Aircraft Servo Valve Hydraulic Test Equipment, rated to 250 kg/cm² / 120°C ATF.

Introduction

Servo valves are among the smallest yet most consequential components inside an aircraft engine. They regulate fuel delivery, hydraulic actuation and dynamic response during throttle changes. Any inaccuracy — sluggish response, improper seat sealing or contamination — can directly affect thrust stability, altitude performance, or even trigger unsafe engine behaviour. Because of this, every servo valve leaving an overhaul facility must be tested under conditions that precisely replicate the pressures, temperatures and dynamic loads it experiences in flight. The Aircraft Servo Valve Hydraulic Test Equipment recreates these exact conditions, acting as the final gatekeeper ensuring that the aircraft's fuel and actuation subsystems remain dependable, consistent and safe.

System architecture & operating philosophy

The equipment is built around an integrated multi-circuit hydraulic architecture that allows the operator to test the servo valve across its entire operating envelope. The primary high-pressure test circuit delivers regulated ATF at both 120 kg/cm² and 250 kg/cm², with stable temperature and flow control. The drain circuit maintains a precisely controlled back-pressure, vital for ensuring the valve behaves the same way it would inside an aircraft engine's internal manifold. A fully separate preservation circuit allows flushing, cleaning and long-term conditioning of the valve without cross-contaminating the main hydraulic loop.

• Functional testing under high-pressure ATF.
• Servo valve priming and de-aeration.
• Temperature-conditioned evaluation up to 120°C.
• Drain pressure emulation to simulate engine manifolds.
• Preservation flushing and storage conditioning.

Thermal control & high-pressure performance

Aircraft servo valves operate in harsh thermal zones, especially near hot engine sections. To simulate these conditions, the system employs dual-channel flameproof temperature sensors paired with a closed-loop thermal control architecture. The plate-type heat exchanger provides smooth and consistent ATF cooling, enabling temperature stability even during extended high-load tests. The high-pressure hydraulic loop — powered by explosion-proof ABB motors and precise Beinlich pumps — allows repeatable performance assessment at both medium and high pressure. The ability to test at 120 kg/cm², 150 kg/cm² and 250 kg/cm² ensures that the valve is validated for realistic flight loads, including transient conditions that occur during rapid throttle transitions.

Filtration & contamination control

Servo valves rely on micron-tolerance internal clearances. Even minute particulate contamination can cause drift, degrade response time, or lead to critical in-service failure. For this reason, the machine incorporates a robust multi-stage filtration chain beginning with coarse strainers and progressing through medium-pressure filters before reaching fine high-pressure filters rated at 6 µm and below, each featuring β-ratios above 1000. Clog indicators provide real-time feedback, prompting filter replacement before performance is compromised. All filter housings and wetted components are manufactured from aircraft-grade stainless steel or aluminium alloys, ensuring compatibility with high-temperature ATF and preventing internal corrosion during long-term operation.

• Suction strainers (100–150 µm).
• Medium filtration (10–16 µm).
• Fine high-pressure filtration (5–6 µm).
• Mechanical clog-indicator alerts.

Operator interface, instrumentation & control philosophy

The control panel gives the operator complete situational awareness during testing. Key parameters — temperature, pressure, flow rate, differential behaviour, drain pressure and electrical consumption — are visible at a glance through a combination of digital readings and high-accuracy WIKA mechanical gauges. A 15-inch touchscreen HMI, integrated with a data acquisition system, ensures that all measurements can be monitored, logged and analysed with high fidelity. Flow control is achieved through a combination of motorised valves, needle valves and precision 3-way valves chosen specifically for high-temperature, high-pressure aircraft applications. Safety features such as flameproof switches, explosion-proof motors, emergency-stop provisions and pressure relief paths ensure that both the equipment and operator remain protected even under abnormal load conditions.

Structural layout & ergonomic design

According to the GA drawing, the system is divided into a working table and a standing platform, enabling a clean separation between operator space and high-pressure rotating machinery. The test cell layout, occupying roughly 3600 × 4200 mm, is compact yet spacious enough for maintenance access. Pumps, motors and hydraulic skids are positioned to allow straightforward serviceability, while the test table and control panel remain at the front of the test cell for operator convenience.

• Clean segregation of test area and power sections.
• Easy access to filtration units, heat exchangers, sensors and valves.
• Logical hose and pipe routing for safety and clarity.
• Compact footprint suitable for aircraft MRO shops.

Safety & reliability built for aviation

All components used — including the flameproof sensors, explosion-proof motors, diaphragm accumulators, high-pressure relief valves and visual level indicators — reflect an aviation-centred safety philosophy. The equipment is designed to withstand sudden pressure deviations, unexpected flow surges and operator errors without compromising the integrity of the test or the safety of personnel. Its multi-layered redundancy ensures that any servo valve tested on this platform is assessed with the same level of caution and precision that governs the aviation industry itself.

Conclusion

The Aircraft Servo Valve Hydraulic Test Equipment from Neometrix Defence Limited is a precision-engineered solution designed to ensure the safety and performance of aircraft servo valves. With high-pressure simulation, thermal conditioning, contamination-control architecture and an operator-friendly control interface, the system delivers complete confidence that every tested valve is restored to flight-ready reliability — an indispensable tool for any aircraft engine overhaul facility where precision, consistency and safety define the operational standard.