Servo Valves And Proportional Valves – Electrical Diagnostics…

Servovalvola flapper-nozzle su banco taratura – diagnostica TFS

Servo valves and proportional valves serve as the interface between electronic control and fluid dynamics. Wear in the pilot system, fluid contamination, or position transducer drift can result in axis positioning errors, pressure fluctuations, and slowed-down cycles. TFS works on single- and double-stage Moog servo valves, direct- and pilot-operated Bosch Rexroth proportional valves (with and without position feedback), the Atos electrohydraulic range, and associated electronic controllers. Diagnostics are performed on a test bench using a signal generator, frequency response measurement, hysteresis and hydraulic zero point checks, and pilot current verification. Repairs require a controlled-contamination environment: TFS employs ultrasonic cleaning procedures and assembly in a filtered atmosphere. For complex systems, TFS integrates valve calibration with the development or updating of control software, both in the laboratory and on-site, on industrial PLCs and dedicated electro-hydraulic drives.

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Difference between servo valves, proportional valves, and electronic controllers

Servo valves (flapper-nozzle, jet-pipe) ensure high dynamic performance and high positioning accuracy but require fluids with very strict cleanliness classes. Proportional valves, whether direct-acting or pilot-operated, are more tolerant of contamination and suitable for standard industrial applications. The associated electronic controllers manage the closure of the control loop. The choice depends on the required bandwidth, fluid cleanliness class, operating environment, and maintenance budget.

Bench testing and hydraulic zero calibration

Bench diagnostics include preliminary ultrasonic cleaning, cleanroom assembly, and testing with a signal generator that explores the entire control range. TFS measures response linearity, residual hysteresis, bandwidth, and calibration current. The hydraulic zero is adjusted mechanically or electrically according to the manufacturer’s specifications. Each overhauled servo valve is shipped with a calibration report documenting operating parameters and compliance with OEM tolerances.

Integration with control electronics and software development

On more complex systems, the valve alone is not enough: TFS also works on the control electronics, parameterizing Bosch Rexroth SYDFE/SYHDFE drives, configuring ramps and PIDs, and developing PLC logic dedicated to position, speed, and pressure control. The software development service supports the commissioning of the hydraulic axis until the required performance is achieved, even at the customer’s production sites. This integration of mechanics, hydraulics, and electronics is the TFS differentiator in servo-controlled systems.

Brands we work with: Moog – servo valves and electrohydraulic actuators, Bosch Rexroth 4WRE and 4WRPE proportional valves, Atos – electrohydraulics and proportional valves, Parker – proportional valves, Hawe – HS servo units for control loops.

TFS services involved: overhaul of hydraulic components, testing and certification, on-site support, control software development, commissioning.

Application sectors: steel industry, presses, Oil & Gas, rail, marine.