--- title: 5 Ways You Can Apply Spool-Type Logic Valves description: This post describes 5 different ways you can use Logic Valves and Pressure Compensators. --- [![logo-1](https://info.hydraforce.com/hs-fs/hub/84685/file-1401344043.jpg)](http://www.hydraforce.com/) - [Home](http://www.hydraforce.com/) - [Contact Us](http://www.hydraforce.com/About_HF/global_locations.html) - [Careers](http://www.hydraforce.com/Employ/Emp-World.htm) - [News](http://www.hydraforce.com/News/Newprds.htm) - [Find Valve by Model No.](http://www.hydraforce.com/Modelnos.htm) # HydraForce Insider Blog ## [5 Ways You Can Apply Spool-Type Logic Valves](https://info.hydraforce.com/hydraforceinsiderblog/bid/36678/5-Ways-You-Can-Apply-Spool-Type-Logic-Valves) Posted by [David Price](https://info.hydraforce.com/hydraforceinsiderblog/author/david-price) on Wed, Mar 09, 2011 @ 15:03 PM - [Tweet](https://twitter.com/share) | 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](http://www.hydraforce.com/Directnl/Dvplogel.htm), [EPFR](http://www.hydraforce.com/Directnl/Dvpre-comp-ele.htm) and [EV](http://www.hydraforce.com/Directnl/Dvvlogel.htm#EVxx-S34). 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. | ![](http://www.hydraforce.com/HFinsider/Spool_Logic_Heroes/Hero_Spool_Logic.jpg) | | --- | --- | 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: | **Bypass Compensator** ![Bypass Compensator](http://www.hydraforce.com/HFinsider/Spool_Logic_Heroes/Bypass_Comp.gif) Maintains a constant pressure drop (EP spring value) across a fixed or variable orifice, thus maintaining proper flow rate regardless of changing load pressures. |   | **Bypass Compensator with Pressure-Compensated Bleed-Off** ![Bypass Compensator with Pressure Compensated Bleed-Off](http://www.hydraforce.com/HFinsider/Spool_Logic_Heroes/Bypass_Comp_Bleed-Off.gif) Built-in flow regulator bleeds-off trapped pressure in sense line. Bleed-off is pressure-compensated, making a proportional circuit more accurate and controllable. | | --- | --- | --- | | **Bypass Compensator with Boost Circuit** ![Bypass Compensator with Boost Circuit](http://www.hydraforce.com/HFinsider/Spool_Logic_Heroes/Bypass_Comp_Boost.gif) Allows for a low unloading-pressure drop while boosting the compensator value only when needed to perform the work. |   |   | | **Accumulator Charging Circuit** ![Accumulator Charging Circuit](http://www.hydraforce.com/HFinsider/Spool_Logic_Heroes/Accum_Charging.gif) Works with a UP10-31 valve to unload a fixed-displacement pump at a low unloading-pressure drop. The EV valve can be sized to handle any flow while cycling to keep a predetermined range of pressure in the accumulator. | | |   **       High-Flow Sequence Valve** ![High Flow Sequence Valve](http://www.hydraforce.com/HFinsider/Spool_Logic_Heroes/Hi-Flow_Sequence.gif) 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](mailto:hydraforce.online@hydraforce.com?subject=Spool-type%20Logic%20Valve%20Application) if you’d like to share your application or ask a question. About the Author: ![](http://www.hydraforce.com/HFinsider/Spool_Logic_Heroes/Scott.jpg) Scott Parker is a Senior Application Engineer at HydraForce. He’s been developing Hydraulic Systems for 20 years. [Contact Scott](mailto:ScottP@HydraForce.com?subject=HydraForce%20Community%20Question) Tags: [cartridge valves](https://info.hydraforce.com/hydraforceinsiderblog/topic/cartridge-valves), [pressure control valve](https://info.hydraforce.com/hydraforceinsiderblog/topic/pressure-control-valve), [logic valves](https://info.hydraforce.com/hydraforceinsiderblog/topic/logic-valves), [pressure compensators](https://info.hydraforce.com/hydraforceinsiderblog/topic/pressure-compensators), [Bypass Pressure Compensator](https://info.hydraforce.com/hydraforceinsiderblog/topic/bypass-pressure-compensator), [Sequence Valve](https://info.hydraforce.com/hydraforceinsiderblog/topic/sequence-valve), [Accumulator Charging Circuit](https://info.hydraforce.com/hydraforceinsiderblog/topic/accumulator-charging-circuit), [cartridge](https://info.hydraforce.com/hydraforceinsiderblog/topic/cartridge) ### Subscribe by Email ### Other related info [![Sign up for Product news.](https://info.hydraforce.com/hs-fs/images/C--Documents%20and%20Settings-dp2-Desktop-Email-Signup-resized-156.jpg?width=171&height=72&name=C--Documents%20and%20Settings-dp2-Desktop-Email-Signup-resized-156.jpg)](https://info.hydraforce.com/HydraForceProductUpdates/) [![describe the image](https://info.hydraforce.com/hs-fs/images/k--sales-training-image%20library-request%20a%20catalog_2-resized-156.jpg?width=172&height=152&name=k--sales-training-image%20library-request%20a%20catalog_2-resized-156.jpg)](http://www.hydraforceleads.com/form/catalogForm.php) [![describe the image](https://info.hydraforce.com/hs-fs/images/K--SALES-TRAINING-Image%20Library-Download%20a%20copy%20of%20i-Design-resized-156.jpg?width=176&height=152&name=K--SALES-TRAINING-Image%20Library-Download%20a%20copy%20of%20i-Design-resized-156.jpg)](https://info.hydraforce.com/download-your-free-copy-of-i-design-v3-today/) [![K SALES TRAINING Image Library Custom Manifold Consultation resized 156](https://info.hydraforce.com/hs-fs/images/K--SALES-TRAINING-Image%20Library-Custom%20Manifold%20Consultation-resized-156.jpg?width=175&height=145&name=K--SALES-TRAINING-Image%20Library-Custom%20Manifold%20Consultation-resized-156.jpg)](https://info.hydraforce.com/Free-Custom-Circuit-Consultation/) ### Follow Me ### News Ticker **[Click Here ](http://www.hydraforce.com/News/News_tickr.htm)to see the latest HydraForce News.** ### Latest Posts ### Posts by category - [cartridge valves (25)](https://info.hydraforce.com/hydraforceinsiderblog/topic/cartridge-valves) - [proportional valves (11)](https://info.hydraforce.com/hydraforceinsiderblog/topic/proportional-valves) - [pressure control valve (8)](https://info.hydraforce.com/hydraforceinsiderblog/topic/pressure-control-valve) - [HydraForce (7)](https://info.hydraforce.com/hydraforceinsiderblog/topic/hydraforce) - [manifold design (7)](https://info.hydraforce.com/hydraforceinsiderblog/topic/manifold-design) ### OTHER RELATED INFO [![describe the image](https://info.hydraforce.com/hs-fs/images/k--sales-training-image%20library-request%20a%20catalog_2-resized-156.jpg?width=172&height=152&name=k--sales-training-image%20library-request%20a%20catalog_2-resized-156.jpg)](http://www.hydraforceleads.com/form/catalogForm.php) [![describe the image](https://info.hydraforce.com/hs-fs/images/K--SALES-TRAINING-Image%20Library-Download%20a%20copy%20of%20i-Design-resized-156.jpg?width=176&height=152&name=K--SALES-TRAINING-Image%20Library-Download%20a%20copy%20of%20i-Design-resized-156.jpg)](https://info.hydraforce.com/download-your-free-copy-of-i-design-v3-today/) [![K SALES TRAINING Image Library Custom Manifold Consultation resized 156](https://info.hydraforce.com/hs-fs/images/K--SALES-TRAINING-Image%20Library-Custom%20Manifold%20Consultation-resized-156.jpg?width=175&height=145&name=K--SALES-TRAINING-Image%20Library-Custom%20Manifold%20Consultation-resized-156.jpg)](https://info.hydraforce.com/Free-Custom-Circuit-Consultation/)