Development and manufacure of a universal hydraulic test rig for proportional and servo valves and cylinders

This paper reports the details of the first locally developed and manufactured universal hydraulic test rig for testing proportional and servo valves and cylinders. Other types of hydraulic valves, cylinders and motors can also be tested using the rig. The drive and control systems of the rig are designed so as to match almost all the prevailing types of valves of sizes up to size 32, and cylinders of diameters up to 320 mm diameter from different manufacturers. In the rig the electro hydraulic servo and proportional valves can be driven in accurate closed loop control systems, and the static and dynamic characteristics of these components can be measured and recorded. Economic considerations were taken into account during the design phase of the rig. The hydraulic tank and its accessories, of the low pressure hydraulic power supply system of the hot strip in the plant, were utilized as the tank of the hydraulic power supply unit of the rig. One main sub-plate was designed, manufactured and used for mounting and matching the porting patterns of the different valves, or the sub-plates of valves, to be tested. Special mounting stand was developed to test the cylinders under load. Results of testing some servo valves using the rig are presented.