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  1. RNDguy

    automating weld of fitting to a small shell

    All of you have given some very good advice indeed, I want to thank all of you for the general enthusiasm, interest and help in this regard. Consensus appears to imply that it is a do-able thing. To respond to some of the suggestions: - We are looking at MIG because this seems to be the...
  2. RNDguy

    automating weld of fitting to a small shell

    Thanks for all the replies. GenB, one of the difficulties we are realising is that because the fittings make the shape of a saddle where they meet the shell, good tracking of the weld may be essential for sound welding. Does this appear to be within the limits of current proven technology with...
  3. RNDguy

    automating weld of fitting to a small shell

    We want to automate the process of welding internally threaded fittings of 3/4" to 1.5" OD to shells of 9" to 12" dia and of 1/8" thickness using MIG. The material of both the fittings and shell is mild steel. Any help/info/tips in this regard will be helpful. Is this even worth pursuing? Thanks...
  4. RNDguy

    WRC 107 calculation on ellipsoidal head

    codeeng, Thank you for your valuable comments. Since I do not have an FEA software available to me, therefore, the best recourse for me is to do what I proposed above and accordingly solve thru WRC 107 method. (Any more comments there?) However, I am going to use a maximum limit for membrane...
  5. RNDguy

    WRC 107 calculation on ellipsoidal head

    codeeng, I wonder how softwares like COMPRESS or PVELITE tackle this? Do they use FEA? If not, they must be doing WRC 107 calculations for external local loads even on knuckle region of ellipsoidal head. So what mean radius Rm would they assume at a point like that? I propose the following: use...
  6. RNDguy

    WRC 107 calculation on ellipsoidal head

    This could be true in the crown portion of the head. But away from the crown, this would be completely wrong. If the vessel supports are away from the crown and not exactly on but near the knuckle region, then local radii are very different indeed. Now here's what article 3.5.3 of WRC 107 says...
  7. RNDguy

    WRC 107 calculation on ellipsoidal head

    To carry out external load calculations on ellipsoidal head, WRC 107 recommends to use a mean radius Rm to approximate local area as a sphere, and then use relevant graphs for spherical shell to calculate local stresses. My question is: what mean radius Rm to use? You see, on an ellipsoidal...
  8. RNDguy

    Assembly configurations in Inventor

    Thanks DesignerMike. Maybe Inventor10 deals with this a little better, however, this still leaves a lot of desired functionality out, like naming different configurations and switching between them at will. I guess Inventor 11 may have configurations??
  9. RNDguy

    Assembly configurations in Inventor

    I use Inventor 9 currently. Ever since Inventor 6, when I first tried to create assembly configurations by using multiple iParts in an assembly and attempted to switch between different versions of an iPart to arrive at different assembly configurations, I have come up against error messages...
  10. RNDguy

    ASME Section I, PG-32.1.2

    Gentlemen, Can I refer to PG-16.4 & PG-16.5, former is for plate undertolerance and the latter is for undertolerance on pipes and tubes. For plates, 0.01" undertolerance is allowed. For tubes and pipes, this is stated: "Pipe or tube material shall not be ordered thinner than that calculated from...
  11. RNDguy

    ASME Section I, PG-32.1.2

    Since ASME is a design code, for it "actual" would mean the actually used nominal thickness. While at the design stage, no pressure vessel or boiler really exists, so the term actual only means what the designer is finally adopting as the value of thickness. I am going by memory, but I believe...
  12. RNDguy

    Hydrostatic testing of ASTs at low temperature

    Ethylene glycol, propylene glycol or triethylene glycol may be good for this application. Many companies make them, try e.g. Lyondell Chemical Company: www.lyondell.com Glycols are the anti-freeze of common parley. Their compatibility with petroleum products is good (I am sure the solution will...
  13. RNDguy

    Flat of a rolled cylindrical part

    jlcochran1: Thanks. I do not know of a solution for joggled and beaded ends, maybe there is one? About manual compensation for the joggled end in flat layout, is there a way of doing this in an .idw file? I guess I can make a joggled end by a simple revolve separately and "attaching" it to the...
  14. RNDguy

    Substitution of steels with same P-number in welding

    Thank you gentlemen, I have posted in another forum and got my replies.
  15. RNDguy

    Flat of a rolled cylindrical part

    How can I make a part in Inventor which is a rolled sheet metal such that its flat pattern is linked and generated. I know this can be done possibly by using 2 folds of 180 degrees each (actually the second a little less than 180 deg to give a gap for butt-welding the longitudinal seam). But...
  16. RNDguy

    Heat Exchanger Tube Defect Assessment

    unclesyd: Any references to read up about MIC? Thanks.
  17. RNDguy

    Heat Exchanger Tube Defect Assessment

    James01, Your woes sound familiar. We make small firetube boilers with CS pipe (yes, schedule 40, A 105 pipe, not tube) as part of one of our products. The shell side is sealed and under vacuum (closed circuit). There is a corrosion inhibitor on the shell side. Most of these boilers never have...
  18. RNDguy

    Substitution of steels with same P-number in welding

    metengr: You are right, I am considering the qualification to be used beyond code application, however, no notch toughness requirement is there. I guess using the same qualification with a different group number is OK in this case. Thanks again for all the help.
  19. RNDguy

    Substitution of steels with same P-number in welding

    metengr: Thank you very much. I could not have imagined to receive a more lucid answer. Regards.
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