×
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

REINFORCEMENT OF OPENING ON FLAT HEAD

REINFORCEMENT OF OPENING ON FLAT HEAD

REINFORCEMENT OF OPENING ON FLAT HEAD

(OP)
UG-39(b) seems to suggest that for openings in a flat head, only half the area required by UG-37 is needed to satisfy the reinforcement requirements for the opening. Is it safe to assume that a head needs only half the reinforcement area of a similar opening on a shell?

RE: REINFORCEMENT OF OPENING ON FLAT HEAD

sp-

A shell and spherical or ellipsoidal or similar head carries the load imparted by the internal pressure through membrane stress. This stress is directly proportional to the thickness. On the other hand, a flat head resists the pressure through bending. The stress in this case is proportional to thickness squared. So very roughly speaking, the required reinforcement provides the same increase in strength if you double the thickness of a shell or take 150% of the thickness of a flat head. Thus, reinforcement of an opening on a flat head requires half of the reinforcement of an opening on a shell. Before we get off debating the details, keep in mind that the concept of area replacement can be debated ad infenatum.

jt

RE: REINFORCEMENT OF OPENING ON FLAT HEAD

Well, sp231, your wording is a bit confusing. The required area is based on the required thickness tr, and this one will be of course different for any given vessel part, be it a shell or a flat head. What you can say is that, for the same tr, the area required by a flat head is half the one required by a shell, but that's exactly what the code tells you.

prex
http://www.xcalcs.com : Online engineering calculations
http://www.megamag.it : Magnetic brakes for fun rides
http://www.levitans.com : Air bearing pads

RE: REINFORCEMENT OF OPENING ON FLAT HEAD

(OP)
prex,
I am trying to compare the area required by UG34(c) and UG39(b)1

RE: REINFORCEMENT OF OPENING ON FLAT HEAD

Perhaps 'ad infinitum'...(ie endlessly)? Other than that, spot on reply to sp231.
Cheers,
gr2vessels

 

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