In Part 1, I covered the force balance in the counterbalance valve and how to calculate the release pressure. But what happens once the valve starts to open? In this article I will discuss how to size the counterbalance valve to insure stability. From the previous article we saw that actuator areas, and pilot ratio as well as resistance at the exhaust of the counterbalance valve all influence the release pressure. We saw that when using just an internally piloted valve the release pressure is higher than when using an internally and externally piloted valve. The advantage to using an internally and externally piloted counterbalance valve is that a lower release pressure means a high system efficiency because the pressure to lower the load is less, so the power requirement to lower the load is less.
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