Accessories for Servo-Hydraulic Testing Machines

The final element in our dynamic testing product portfolio is the manufacture of all the necessary accessories. The portfolio is constantly being expanded through a program of continuous development and the inclusion of new products, allowing us to satisfy our customers' most demanding quality requirements while continually improving the quality of our products.
Accessories for servo-hydraulic testing machines

Hydraulic Grips for Servo-Hydraulic Testing Machines

Body Over Wedge for servohydraulic testing machines

The "body over wedge" hydraulic grips for servo-hydraulic testing machines provide a high level of operating convenience.

When used with servo-hydraulic testing machines they are connected to the existing pressurized oil supply. A small power pack is required for use in static materials testing machines.

Advantages and features of hydraulic specimen grips for servohydraulics

  • Suitable for static tensile and compression tests and for fatigue tests under pulsating and alternating loads
  • Optionally available for superimposed torsion loading
  • Nominal forces 25, 100, 250 and 500kN
  • Interchangeable jaws for flat and round specimens of different dimensions
  • Radial jaw guides prevent unwanted axial stresses in the specimen
  • side-opening design for easy specimen change
  • adjustable gripping pressure for ‘soft’ specimens such as wood and plastics.

Technical data, Fmax 25 kN

Technical data, Fmax 100 kN

Technical data, Fmax 250 kN



Servo Valves

Servo valves are used in closed control loops for high-accuracy control of hydraulic energy, with multi-kilowatt hydraulic power controlled by input signals in the milliwatt range. Extremely severe demands are placed on servo valves used in materials and component testing. They must respond to a wide range of set-value signals with equal precision at extremely high or very low test speeds, with short or long travel. 

Advantages and features of Zwick servo valves

The correct choice of servo valve is determined by the size of the servo-hydraulic testing actuator (nominal capacity) and the required operating point (defined by force, travel and frequency). Zwick uses a suitable computer program to determine the performance characteristics of a given single testing actuator-servo valve combination.

  • 2-stage servo valves available with a nominal flow-rate of 4 l/min to 230 l/min.
  • Servo valves can be used in systems operating at 210 or 280 bar.
  • High response valves available for particularly high dynamic ranges.
  • Servo valves available as 4 or 5-port valves for separate pilot pressure connection
  • Standard connection port pattern to ISO 10372-04 for valves up to 75 l/min.