×
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

Vacuum on Pipe

Vacuum on Pipe

Vacuum on Pipe

(OP)
For large diameter pipe under full vacuum (FV) attached to pressure vessel, I always check using ASME VIII, Div 1 external pressure curves.

This may be conservative but are there other ways of verifying the vacuum loads??

RE: Vacuum on Pipe

that depends, what does the specification say?
local regulations/standards?
any requirement from the insurance company that requires the parts to be certified by ASME?
If there is no requirement whatsoever... the pipe can be verified with the formulas for pipes under external pressure in text books like timoshenko's, roark & young etc...
HTH

saludos.
a.

RE: Vacuum on Pipe

Assuming the pipe is covered by a piping code, you need to follow those rules.  For example, if it is B31.3 piping, teh Code refers to the Section VIII, Div 1 rules for design for external pressure.

RE: Vacuum on Pipe

The Steel Plate Fabricators Handbook, by SPFA, covers the design of shells for external pressure, but it is intended for thin shells, not pipe.  Most piping components would have much higher D/T ratios than storage tanks.  If you have the latitude, you may want to consider using the ASME VIII rules, but lower the factor of safety to something below three.

Steve Braune
Tank Industry Consultants
www.tankindustry.com

RE: Vacuum on Pipe

A correction to previous post...  I meant to say that most piping components have a "much LOWER D/T ratio" than tanks.  Sorry.

Steve Braune
Tank Industry Consultants
www.tankindustry.com

RE: Vacuum on Pipe

Look in 'Steel Penstocks' - ASCE Manuals & Reports on Engineering Practice No. 79.'  (ISBN 0-87262-951-1)
Pages 124 to 137
Section 6.2 - Design of Steel Liners for External Pressure.
This reference is for steel tunnel liners concreted into rock.
Figure 5.1 (page 116) indicates critical collapse pressure vs ring deflection for a perfect circle & a buried pipe condition.

See also AWWA M11 (Steel pipe - a guide for design & installation) for more info.

Barry

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