×
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

PRESSURE TESTING VENTURIS

PRESSURE TESTING VENTURIS

PRESSURE TESTING VENTURIS

(OP)
hi guys,could anybody outthere help me,im having alot of trouble sealing off fabricated venturis for pressure testing sizes are 36'' 900Lb, 48'' 6oolb test pressures 206bar and 120 bar using spiral wound graphite filled gasket onto scrolled faces, bolts are 2 1/2'' and 2 3/4''.
i am using hydraulic torque wrench to correct settings,am i using right type of gasket or should i be using some kind of sealant with them would appreciate your help/comments

RE: PRESSURE TESTING VENTURIS

(OP)
forgot to say they are carbon steel flanged raised face

RE: PRESSURE TESTING VENTURIS

Have you got enough flange for your size and pressure?
What is the code or standard?

On such a large flange I would be very careful if I was very near the allowables for a particular flange. It also get a little more interesting as a flange advances in diameter.
You should be using more than one hyd wrench at at time, a very minimum of 3.

Can you come back with more detail like torque on nuts and tightening secquence?

Number of bolts/studs and material?

 

RE: PRESSURE TESTING VENTURIS

On a large diameter like that, we have had problems with the spiral wound gaskets.  What I prefer is a 1/16" thick carbon steel ring that is faced with .030" of graphite on both sides.  It's real tender to handle but it doesnt't leak.  Also, like unclesyd said, have you got enough flange?  Especially large diameter like this that barely make appendix 2 calcs or b16.47.  one hydraulic torque wrench at a time is hard to seal unless you go in extremely small increments.  Are you useing the correct bolts with the correct lubrication on them for correct torque?

RE: PRESSURE TESTING VENTURIS

(OP)
HI GUYS,FLANGES ARE ASME B16.5 STANDARD ,TIGHTENING SEQUENCE IS 180° OPPOSITE AT 30% ,60%,100% 0F TORQUE.
MAX TORQUE FOR 2 3/4 '' bolts 10250Nm .BOLTS AND STUDS ARE B7 2H

RE: PRESSURE TESTING VENTURIS

(OP)
also using copperslip on threads to get max load on bolts.

RE: PRESSURE TESTING VENTURIS

Your torque number is low.

What bolt stress are you trying to achieve?

How many wrenches?

What is your design pressure and temp as your test pressure  is near the max?
 

RE: PRESSURE TESTING VENTURIS

(OP)
1 wrench, design press 128 bar and 80 bar respectively,temp @ ambient 20°c but probably less in conditions,youre probably right unclesyd about more wrenches but conditions don't lend themselves to using more could it be a gasket issue like vessleflab says.torque settings came from gasket supplier.

RE: PRESSURE TESTING VENTURIS

I'm a little confused as to the flange and the bolting size. Not saying they are not made but I've never seen a 16.5 ASME flange above 24". Normally you would use ASME 16.47 Series B, A or MSS-SP44 for 26" and above. The stud call out for the 36" is 20-3 1/2" and for the 48" 24-4" studs.
As far as the gasket I don't think you have properly seated it to where it will hold.

I hate to ask but can you comeback with the number of studs and exactly which flange you have?
 

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