×
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 Rating of Atmospheric Storage Tanks

Vacuum Rating of Atmospheric Storage Tanks

Vacuum Rating of Atmospheric Storage Tanks

(OP)
I have an atmospheric storage (actually 20 in w.c.) tank with a flat bottom, 2:12 cone roof.  It's not built to API 650 but looks a lot like one.  I was wondering how high of vacuum rating it could take.

API 650 specifically says limit the tank to 1-inch w.c. external pressure.

FM Loss Prevention Bulletin No. 13.23 says 1 3/4-inch w.c. vacuum for roofs having at least 3/16-inch roofs.

Are there any other industry guidelines w/o perform a rigorous calculation???

RE: Vacuum Rating of Atmospheric Storage Tanks

API 650 is generally recognized as the reference code for flat bottom cone roofed tanks.  You can analyze all elements using Compress or some other engineering design program.  I would be very careful about making vacuum assumptions particularly for an API tank.  I have been in the tank and vessel business for 30+ years.  During that time I have seen few failures due to pressure but many due to vacuum.  

RE: Vacuum Rating of Atmospheric Storage Tanks

the cute answer is ..not much, These are large thin walled pressure vessels and are not designed to take external pressure like Kennyrae said, lots of tanks get collapsed due to vacuum not many blow up

RE: Vacuum Rating of Atmospheric Storage Tanks

Depending on your diameter to thickness ratio there are two ASME Code cases that might be of assistance to you.
Code Case 2286-1 (ASME VIII Div 1 and Div 2) or
Code Case N-284-1 (ASME III Div 1)

Both of these limit the D/t ratio to 2000:1 with the nuclear case also limiting the minimum thickness to 1/4".

Caution should still be applied, especially when dealing with existing tanks since deviations from true circular form are generally the cause of vacuum type failures.

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