I have used both 2d and 3d design for pressure vessel. My personal choice would be 3d.
However I would not recommend it to every pressure vessel fabricator.
Advantages of 3d:
- mistakes are reduced as designer is working with model, and each part is “assembled” into model same way as it will be...
I was asking myself same question, then I see that pipe thickness is given. If you calculate MAWP of the pipe you can get an idea of blind plate thickness. But that is just an idea, and I would not recommend anybody anything based on that.
As domed head might seem as a better solution, flat...
Shouldn’t internal pressure always act on the inner wall of a vessel?
My conclusion is that the Code formulas are using Rm:
For circ stress:
Rm=Ri+0.6t
Rm=Ro-0.4t
For longitudinal stress:
Rm=Ri-0.4t
Rm=Ro-1.4t
Why?
Yes, it is the same question. I didn’t see a definite answer.
It is not a job interview and I am working in pressure vessel industry for some time. I did number of calculations and never questioned why formulas are different. I just took them for granted.
Hello,
I have a question regarding a shell calculation. Why is code using different formulas if it is outside or inside diameter?
If long. stress formula is Sl=P*Rm/2t, why is code using P*(Ri-0.4*t)/2*E*t.
Or if Circ Stress is Sc=P*Rm/t why it is used P*(Ri+0.6t)/E*t
Why is, for the...
Section VIII is rules for pressure vessel design.
Section IX is welding qualification.
When you build pressure vessel per Section VIII by welding, you are using Section IX for welding qualification.
Thank you Tom, it is clear that those formulas are coming to same result.
The reason for my question is that I will be interviewed soon and this is the type of the question that I anticipate.
My interest is in the relation of the code formulas to the stress theory.
I am not sure if that is the root for the formulas. I think that is the base for Division 2 calculations (maximum shear theory).
My approach is that (for circ. stress) Rm is neutral line diameter of the shell. In that case Rm=Ri+0.6t would mean that that line is 60% inside of the thickness...
I think that I have posted it on "boiler and Pressure Vessel" forum, haven’t I?
This is only theoretical question, as where are those expressions coming from?
I am working with ASME Section VIII for some time and I was not able to find an answer, yet.
I have a question regarding a shell calculation. Why is code using different formulas if it is outside or inside diameter?
If long. stress formula is Sl=P*Rm/2t, why is code using P*(Ri-0.4*t)/2*E*t.
Or if Circ Stress is Sc=P*Rm/t why it is used P*(Ri+0.6t)/E*t
Why is, for the longitudinal...
Thanks for the input.
My problem is not as simple. I have multiple openings on flat head (b 16.5 blind flange) with LWN flanges.
Minimum distance is 3/16” less than required by UG 36 (2.5*(d1 +d2)). As UG 36 is mentioning unreinforced opening (it maybe worded differently, I do not have code at...
Well, it is UHA 44 Table. Design temperature range listed in the table is above 580°C. My design temp. is quite lower. Is there some other reference for cold forming of SS 304?
We have a 3/4" thk plate that we are rolling to 16" OD. material is SS 304. Per UHA 44 and strain is about 5%, and UHA 44 table is listing 304 material to be good up to 20% of strain.
Everything looks OK, however, my problem is design temperature of 250°C. UHA-44 table is referring to...
