Typical Problems and Potential Solutions

The most common problem experienced with counterbalance valves is instability.

Sun offer a large range of different types of counterbalance valves to try and satisfy the wide range of application problems.

Most applications will work with the standard 3 port counterbalance valves but it is useful to have other cartridges to try which will fit into the same cavities when problems do arise.

Simply trying different types of cartridges does not appear to be a very scientific method of finding a solution but often is the quickest. The problem particularly with many mobile applications is that there are so many changing parameters such as variable speeds, loads and geometry that it would be virtually impossible to find solutions with either calculation or some form of computer simulation.

The problems appear generally in two main forms, instability and/ or noise. Often however the problems only occur intermittently and under certain operating conditions. It is important to obtain as much detailed information about the conditions when problems occur to enable a satisfactory solution to be found. Sometimes compromises may need to be made as the solution to the problem may affect the efficiency of the machine in other operating conditions.

It is important to mention at this stage that it is wrong to assume that problems of instability are always due to the load control valve. The two most common alternative causes of instability are trapped air and cylinder seal stick- slip.