×
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

Hydraulic Piston Actuation Failure Modes

Hydraulic Piston Actuation Failure Modes

Hydraulic Piston Actuation Failure Modes

(OP)
What are the possible reasons for a hydraulic bind occuring in the lock chamber of an hydraulically actuated piston designed to stroke a mandrel behind locking segments which then expand over a load shoulder to grip a groove profile on a seperately standing hub.  This situation is relevant to the functioning of subsea flowline connectors for subsea completions.  Sometimes a secondary release mechanism is employed, but what brought this question up is even if you use a secondary release mechanism, how will that overcome the hydraulic bind in the primary piston locking chamber without being able to vent that chamber. If you could vent the chamber that would bleed it off and eliminate the bind... unless my understanding of a bind is inaccurate in which case, I stand to be corrected.

RE: Hydraulic Piston Actuation Failure Modes

If I understand your question, you are asking what might cause a cylinder to bind (NOT BE ABLE TO MOVE WHEN SIGNALLED TO DO SO  AT THE PRESENT AVAILABLE PRESSURE AND WORK)

In my experience I have come across these situations where a cylinder is mechanically resisted enough that the available hydraulic pressure against its area was not enough to make it either Extend or Retract or both.

Damaged Tube wall such as a dent that kept the piston from passing the damaged area.

Damage tube walls from lack of lubrication that  caused scoring and galling of the tube.

Seals that were extruded into the clearance between the piston and tube wall. This usually happens when the piston clearance is too much due to over honing.

Side load on the Piston Rod causing the piston to contact one side of the tube so much that hydraulic pressure could not move it.

Over sized piston of a material that expands from heat more than the tube and causes binding after a length of run time.

Mechanical binding of the driven device.

There may be other reasons but these are the ones I have seen.

Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us

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