×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Counterbalance Valve

Counterbalance Valve

Counterbalance Valve

(OP)
Can someone explain to me how a Direct Acting Counterbalance Valve (Parker BC6PFV) works?  Does it need pressure on both sides in order to open?

RE: Counterbalance Valve

It might be easier to answer the question to know what kind of circuit you are using it in.  But to clarify your nomenclature, if I might, it's not really Direct Acting but Direct (Pilot) Operated as opposed to the optional Remote (Pilot) Operated.
See http://www.parker.com/Products/EPD/EPDResults.asp?body=pdf%2Easp%3FPSID%3D985&rnd=10%2F19%2F2005+9%3A34%3A50+AM
To make an example how this might work, suppose you were trying to safely lower a load while retracting a cylinder.  You would plumb from the blind side of the cylinder to the valve "pressure inlet".  Since the line mounted model has 2 optional inlets, you WILL have to plug the other one.  Then the "pressure outlet" would go to your directional valve.  While holding the load, you will be inducing pressure from the load to the valve so the spring setting has to be sufficiently higher to hold the load.  As you begin to retract, the pressure going to the rod side will have to induce a pressure sufficiently high on the piston side to force the valve/spring open.  Think of it as really just a direct-piloted relief with a built-in bypass check.

Most of my experience has been to use the remote-piloted version where the remote pilot goes to the rod-side.  This usually allows the valve to open with less induced pressure on the piston side.  If the load tries to run away, by definition the pilot pressure drops and the valve closes.  But all this happens smoothly without the chatter you might get using pilot operated check valves.

Hope this helps.

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!


Resources