×
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

Piping Leakage Testing

Piping Leakage Testing

Piping Leakage Testing

(OP)
I need to know why it is not recommended to isolate the section of piping that we want to test using isolation valves (butterfly or gate valves) , always they used blind flanges for clsing both ends , is it beacuse we may have leakage from the valves or the pressure may damage the valve ????

RE: Piping Leakage Testing

The valve body should hold appropriate hydrotest pressures, but the internals of the valve may be damaged, seals squashed and stems and disks bent by full hydrotest pressures across the valve.

"I'm all in favor of keeping dangerous weapons out of the hands of fools. Let's start with typewriters."
- Frank Lloyd Wright (1868-1959)

RE: Piping Leakage Testing

Valve leakage to the external environment may, by some, be considered as an indication that a hydrotest of an assembled piping system has failed.  Others feel that a valve stem packing which weeps at hydrotest pressures but seals tight at design/relief pressure is acceptable.

Leakage ACROSS (ie. through) a closed valve is NEVER considered as a failure condition for a hydrotest.

Accordingly, you can decide either to trust the manufacturer's test of a flanged valve, or test it in the open (or part open) condition with blinds/blanks on the discharge of the valves, such that valve body seals and packings are part of the test.

Fundamentally this is the owner's call.

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