Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

3-Position Valve Needed

3-Position Valve Needed

3-Position Valve Needed

I have an application where I need a pneumatic valve to have 3 states.  One of the work ports would be plugged, the other would be connected to a bladder  The "normal" state would have the work port open to exhaust.  The other two states would switch between two different pressures.  Could someone help me with the plumbing and the valve selection.  I would rather not use two valves for this.

RE: 3-Position Valve Needed

In just a quick read, could you use a normal two solenoid, 3 position, spring centered valve? I don't know what brand of pneumatic, but many hydr valves are available open center, P to T. Then, connect Work port to P, solenoid 1 A or B is to pressure one, sol 2 is to pressure 2. This does require going through neutral when changing pressures.


RE: 3-Position Valve Needed

Use a spool type 5-Way 3 position with the center condition having "1" ("P")open and "2" ("A") and "4" ("B")connected to (1)("P") to atmosphere. Connect port "3" ("E1") and "5" ("E2") to the different pressure inputs.

Connect ports "2" and "4" to the inlets of a shuttle valve and the outlet of the shuttle valve to the work.

You will probably have to plumb an external pilot supply if the valve is not direct solenoid activated. Also when you want different pressures you will pass thru the work ports open to atmosphere and lose some air in the transition.

Bud Trinkel CFPE
fluidpower1 @ hotmail.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close