Max thickness / high pressure
Max thickness / high pressure
(OP)
Is there as per ASME VIII div 1, any relationship between the maximal thickness of metal sheets for a pressurized vessel and its diameter. I need to make the design of a CS drum of 387.9 bar g / 93.3°C design conditions. Diameter is 1625 mm / height = 3000 mm TL to TL
The thickness is expected to be very high. Is there a maximal thickness for the shhet of metal used to built this vessel or do I need forged material ?
Thanks
The thickness is expected to be very high. Is there a maximal thickness for the shhet of metal used to built this vessel or do I need forged material ?
Thanks





RE: Max thickness / high pressure
You are out of the scope of Section VIII Div.1, see U-1(d) pressures exceeding 3000 PSI. So try Div. 2. Still it is possible to keep your vessel in Div. 1 but you need to preform some additional calculations at the satisfactory of your AI.
Good Luck,
Gert
RE: Max thickness / high pressure
However check the new Div.3 of ASME VIII for high pressure vessels.
prex
http://www.xcalcs.com
Online tools for structural design
RE: Max thickness / high pressure
The information you get from Section 8, div 1 will just tell you how thick of a wall you need. I don't have any knowledge of Division 1, but I know for Division 3 the materials I can select from are limited. We are making a vessel right now with a 14" wall thickness. I may be able to find a 14" thick plate, but if Section 2 says that for this material I am only allowed to have it 2" thick then I must look for a new material.
Specifically for Division 3 all of my vessels are forged using SA-723. For nearly 30 years the company has been making vessels out 4340, forged and heat treated, however section 2 only allows 4340 to be used as bolting material.
RE: Max thickness / high pressure
kyong
RE: Max thickness / high pressure
I agree with kyong. ASME Sec. VIII Div. 1 can be used for more than 3000 psi. However, Div. 2 is more economic. Please comment.
RE: Max thickness / high pressure
RE: Max thickness / high pressure
I think the section VIII rules refer to a different design code or appendix for diameter ratios above some value, perhaps 1.6:1
The wiser method is to use a ribbon wound multi layer pressure vessel, as used in ammonia reforming work overseas. Unlike monolithic vessels, a crack will not propagate to vessel failure in a mulit layed vessel, and the thernal stresses are bounded to lower values. Also, the lead time is MUCH shorter.