×
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

SecVIII UG53(c) circumferential ligament for adjacent long. rows

SecVIII UG53(c) circumferential ligament for adjacent long. rows

SecVIII UG53(c) circumferential ligament for adjacent long. rows

(OP)
ASME Sec VIII, UG53 instruct Ligament efficiency determination.
I try to design a collector pipe (D:273mm) with drilled holes
(similar to figure UG-53.1)
24 holes with (d:50mm, p:89mm)
and 2 rows of holes,
distance between two adjacent rows:65mm
As per UG-53(c), can you tell me steps to determine circumferential ligament?

second question:
65mm is distance from top view of rows,
can I consider the distance as "Arc Length" on Collector pipe? (to determine circumferential ligament)

RE: SecVIII UG53(c) circumferential ligament for adjacent long. rows

Termoguven,

The circumferential ligament efficiency chosen for your design depends on how you are doing the radiography.  E = 1 if the radiographic requirements of UW-11(a)(5)(b) are met.
E = 0.85,if no radiaography is to be done, for circumferential butt joints and longitudinal butt joints connecting seamless vessels, vessel sections or heads provided that these welds are type 3, 4, 5, or 6 joints as described in UW-12.

hope this helps  

RE: SecVIII UG53(c) circumferential ligament for adjacent long. rows

1) Long.p=65 mm, d= 50 mm
long.efficiency (p-d)/p=0.23
2) In my opinion you are required to consider p=the arc lenght at mid header thickness.
As you have only two rows of holes on the header circumference, you could consider also the reinforcement per UG-37. However with your figures the circumferential ligament shouldn't be governing, so OK go on with UG-53.

prex

http://www.xcalcs.com
Online tools for structural design

RE: SecVIII UG53(c) circumferential ligament for adjacent long. rows

In my opinion"prex"is correct. With due respects to MarcoE,
beware of the UW-12 trap. E=1 in this case. Please refer to
Interpretation VIII-I-92-32 and VIII-I-01-63. Seamless pipe is treated the same as welded and you are penalized in UW12e

RE: SecVIII UG53(c) circumferential ligament for adjacent long. rows

The number figured by Prex is correct for the longitudinal joint efficiency, however,  the 'circumferential efficiency' (what termoguven is asking for) is not figured by the equations given in UG-53(b)(1).  

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