Folks,
I'm trying to find a source that would describe how to axisymmetrically model a flanged joint. Specifically, I have always made an equivalent plane strain "bolt" by matching both the cross sectional areas and the moments of inertia for a single stud (bolt) and the equivalent axisymmetric...
Okay, a while back I asked about how to create a thread (or spring) helical pattern in CAE. Duh, of course the answer was to specify a pitch when rotating a sketch to create a solid.
Now to the next level, I want to create a small section of tapered thread. This means that I have to model a...
I agree with khardy about the "proper evaluation". I have run into this exact senario a few times for a few clients. Rather than looking for loop holes, etc, I have just built quick FEA models of the nozzles to show that even during hydro conditions the nozzle stresses are acceptable.
You...
For standards used to perform air tests on vessels that consider stored energy, etc., there is a decent document developed by NASA. I will try to find the document and attach it in a follow up post.
It was used to show management at the refinery that used to work at that air testing (~250 psig)...
You can use the new Section VIII Div. 2 to perform a more detailed fatigue assessment of a Div. 1 vessel. The new S8D2 (along with the new API 579-1/ASME FFS-1) cover off the fatigue design better especially for welds where the structural stress method is used.
As for the controling...
Just wondering if anyone out there knows where the equation for the triaxial strain limit in the new S8D2 5.3.3 comes from? It is also in the new API 579. Specifically I am looking for a derivation of the equation so as to determine how the m_2 and alpha_sl coefficients come from.
el=elu x...
I have found "Above Ground Storage Tanks" by Philip E. Myers to be a decent resource for tank design in general with some good info on roof design. Check it out on Amazon.
I am trying to find a range of values for film coefficients on the internal of an 8" pipe. Problem is, I don't (as yet) have much info on the fluid other than it is mixed hydrocarbons, ~950°F, with a flow rate in the range of 147000 lbs/hr.
I just don't have a good feel for what the range of...
Thanks for the discussion. I did have an issue with calling the nozzles stresses secondary. My issue is that I question myself because when I read the 2007 section 8 div 2, bending in the nozzle wall is to be treated as secondary. This is in the table for a description that says for all...
I found the WRC bulletin and will read up...I don't have access to the older S8D2...TGS4, do you know where I could find the "criteria" document you referred to..?
Thanks for the help.
Ryan
JStephen,
I don't have my 650 handy right now...but I thought there was a figure that showed weld spacing both in the floor and shell. I thought that on that figure it gave guidelines on the angle between the shell and the lap weld seams. I will check my book on monday..
Ryan
Okay, before I get in trouble, I know that there are a couple of threads out there on this topic...but as yet I am not satisfied. I am trying to analyze a nozzle (specifically the nozzle wall) using the 2007 ASME section 8 div 2 (S8D2) analysis.
First of all, my nozzle configuration is made up...
If you froze a pipe you may way to do some diameter checks to make sure the pipe hasn't dilated significantly. Especially look near any restraints (supports, vents, drains, tees, etc).
Even if you find some dilation, you could probably apply the general 1% rule for out of roundness from most...
pipe15,
I have two catalogues that list SRE's over 24". One goes up to 30" and the Taylor Forge goes up to 48! I am looking for an ASME/ASTM reference for these sizes...but havn't found it yet. I don't have my ASME stuff with me...doesn't B16.28 or B16.9 mention something about the larger...
I here you about the scary pd pumps. I have been in the field during a shutdown and had the inspector call me over to a hydrotest because of a "problem". I knew that the pipe in question was 150# class...when I arrived the inspector asked me if going over the test pressure (~350 psig) was...
I agree with the fill up considerations to ensure that the air is out of the system. I'm not sure about time for stress equalization. As long as I do not shock the system (piping or a vessel) the stresses are, for the most part, primary (load controlled).
While the 10 psig/minute that zdas04...
I understand about the use of small pumps...but...during a major shutdown of a operating unit, the practice we use is to hire a single contractor for all hydros. This contractor can fill the lines with water (or glycol) and pump up with one unit.
Aside from the pump issues, what would people...
A co-worker and I were discussing a specification for hydrotests of piping and pressure vessels. While there is a lot of information on temperature limitations during a hydro (to avoid brittle fracture, etc), I can't find anything that provides guidance on pressurization rates. For example, if...
