| Someone recently joked with me that I’ve never created a circuit that didn’t have at least one Logic Valve in it. HydraForce model numbers for these valves begin with the prefixes EP, EPFR and EV. Typically, these valves are piloted-closed, vented-open, or used as pressure compensators or regulators. I use them often because they are versatile, and they have low pressure-rise and pressure-drop characteristics. |  |
On our catalog pages for these valves, we describe them as: “hydraulic directional element, with multifunction potential when used with other directional, pressure, or flow control devices.” Talk about a vague (albeit true) statement. So, to demystify this situation a little, I started to think about all the different ways spool-type logic valves can be used in integrated circuits. I’ve sketched up some generic circuits that show different ways in which we use spool type logic valves:
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Bypass Compensator
(EP spring value) across a fixed or variable orifice, thus maintaining proper flow rate regardless of changing load pressures. |
Bypass Compensator
Built-in flow regulator bleeds-off trapped |
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Bypass Compensator
while boosting the compensator value only when needed to perform the work. |
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Accumulator Charging Circuit
Works with a UP10-31 valve to unload |
High-Flow Sequence Valve
Most sequence valves have limited
flow capabilities. However, a high-flow
circuit can be accomplished by using a
large EV valve along with a small RV valve.
Do you have another Vented Spool-Type Logic Element Application?
Do you have any questions about any of the circuits I describe here?
Shoot me an email if you’d like to share your application or ask a question.
Scott Parker is a Senior Application Engineer at HydraForce.
He’s been developing Hydraulic Systems for 20 years. Contact Scott
