Location of saddles 1

[sbush]

Is there any rule or guideline for locating horizontal vessel support saddles? I am refering specifically to the distance from the weld line or tangent line of one head to the center line of the corresponding support saddle. Our vessels are typically 96" to 120" diameter by 16' to 32' in side shell length, 1/2" to 7/8" thick, mild steel construction, no consideration for wind and/or earthquake loads.

S. Bush

http://www.water-eg.com

 

[codeeng]

Saddles for large dia, thin wall vessels should be located within 0.5R so that they are stiffened by the heads. Otherwise try to put them so the stress at midspan is approximately equal to the stress at the saddles. Saddle spacing should not be less than 0.6L in any event. For the sizes mentioned you should be ok with 0.8L

 

[MJCronin]

SBUSH,

I have had access to several "inhouse" company guidelines about pressure vessel sizing and specification.

For horizontal vessels, each one specifies 1/4 of diameter (or 0.5R)as the recommended distance from tangent line to the center of the welded support saddle.

You may find a more comple discussion of this in a reference text such as the Harvey or Bednar books

Anyone else out there have a source for this rule ?

Was this issue discussed in that classic "LP Zick" paper of the 1950's ???

MJC