×
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

why must globe & gate vale must be open duratin in test

why must globe & gate vale must be open duratin in test

why must globe & gate vale must be open duratin in test

(OP)
in piping  we full open the gate & and globe valve
after that we test the line
 why?

RE: why must globe & gate vale must be open duratin in test

This might be your test package for test whole system. You can test each line without pass through the valves. However, you have to use more times for testing.

RE: why must globe & gate vale must be open duratin in test

What do you mean by open fully; as opposed to shut or partially open?  Some valves have to be backseated when open to prevent leakage around the valve stem.  

RE: why must globe & gate vale must be open duratin in test

under any condition can we tie flat face flange to raised face flange

RE: why must globe & gate vale must be open duratin in test

ahmedsabry1976,

Using raised face flange with flat face
Thread378-13410

Flat face and raised face
Thread378-29732

RE: why must globe & gate vale must be open duratin in test

qeqe - because if the valves where closed the line pressure might not reach the rest of the line. Gate valves are isolation valves. Globe can have tight shut off. I guess you want to pressure test the whole line???

RE: why must globe & gate vale must be open duratin in test

I assume that you are checking a line where globe and gate valve come in that section.
You cannot belive that these two valves even if they are adjacent, will hold the pressure. No matter how tight you close, they will pass and they do pass. Even if these two valves pass two drops of water, you can see noticable pressure drop. If you need very small leak through these valves, you will need mention, specially, tight-shut-off valves and class..., depending on the leak you expect.

So, it is best to keep these two valves and do the test, so you are sure whole segment is subjected to test pressure.

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