Actually you can't choose tresca as failure criterion in ansys. By the way, NB-3212 is intended to use with stress classification method and linear analysis.
Rules for the plastic analysis are given at NB-3228 and the paragraph doesn't force any particular theory of failure. In my opinion the...
If it's a butt welded category C joint, radiography is required. Radiography is not required for corner joint and it's impossible. That's how I understand it.
However, our qm states that shell to tubesheet joint is butt welded and it cannot be designed according to fig .UW-13.2 (b), (c) and (d)...
Could you please explain where it is said that for unfired steam boilers with design pressures greater than 50 psig the tubesheet to shell joint should be butt welded (as shown in fig UW-13.3) instead of corner joint (as shown in fig. UW-13.2). Thank you for your answer! I just want to make this...
My question is about a tubesheet to shell joint of fig. UW-13.2 (b), (c) and (d). Is this type of joint a butt weld? Section IX defines butt weld and according to it, it's not a butt weld.
This is because degree of NDT of the joint and does it fall under the scope of UW-2(c) which reads "...all...
I have verified every build of compress with calculations using mathcad. basically I calculate mostly used elements like shells, heads, tubesheets.
It's a bit annoying since compress is well verified (and documented as well) by codeware in my opinion. I use older (and sometimes buggy) software...
Compress does not calculate the lug itsef but stresses in shell caused by loads on lug. That's why shape of the lug is (almost) irrelevant. If you are interrested in stresses of the lug itself use basic strength of materials or FEA.
I don't understand what "channel shape" but if you give us an...
TEMA tells how to make calculations, but its very complicated procedure. EN 13445 is usefull too and as far as i can tell the method is very similar to asme. AD 2000 has also method for thick bellows.
I haven't looked the methods of UG-39(c), but does these methods take boundary conditions (like thermal expansion or support of tubes and support provided by pipe in central opening) into account?
I'm desiging same kind of tubesheet, but the tubesheet OD is about 2000 mm and hole is 900 mm and...
OK, now I understand your point.
We are talking about fatigue, and SN (stress-life) curve for carbon steel differs significanly from curve of stainless steel (or nickel alloy) or curve of welded bellows.
Standard EN 13445 provides SN curves for austenitic (cold formed) and ferritic steels...
Just attach your 3" nozzle to bottom head and forgot 90 deg elbow and the hole in support skirt when doing calculations with Compress. You may analyse elbow and hole in support skirt by hand if you find it reasonable.
I recommend you not to model your vessel with compress but just make...
antoniof:
I have been thinking this same problem. I have been using higher seating stresses for gaskets to get higher bolt loads because I know that bolting loads will be higher than App 2 calculations predicts.
However, increase of bolt loads doesn't affect thickness of the flange too much...
It would be helpfull if user was able to input weight of the vessel in support calculations. It's usually the case that vessel weight calculated by compress is different than actual vessel weight and I have to correct vessel weight in compress by adding equal mass that makes vessel weight...
