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Recent content by benensky

  1. benensky

    Dims from 3D vs ISO 2768

    Michal77-I would believe that would be a stretch to say it does since section 1 (Scope) says, “to simplify drawing indications,” 3D models are not generally considered drawings. If your customer is sending you a 3D model or visa versa there would need to be a statement like this on the purchase...
  2. benensky

    basic dimensioning of holes, c'bores & c'sinks per ISO standard

    Thx for all the replies 1-KENAT :(I like the all cap’s. That shows you are a real designer, not taking the cap’s lock off since you are creating text in drawings most of the time). Are your recommendations from experience? 2- KENAT :(Do you know if the c’bore and c’sink standards deal with...
  3. benensky

    basic dimensioning of holes, c'bores & c'sinks per ISO standard

    I am new to ISO drawing and have a question on dimensioning holes. What standard do you use? Granted I could purchase the, "ISO Standards Handbook - Technical drawings" but it is expensive and has standards I will not use and do not need. I am asking for guidance on the ones I will use. I...
  4. benensky

    Valve passing at site

    BillBirch is right. I am a valve designer and we test and design our valve to seat at 110% of rated pressure (MSS SP 61 section 4). The valve shell is designed to meet or exceed 150% (Same standard section 3) ANSI B16.5 also requires the "flange fittings" to pass a 150% rating test (section...
  5. benensky

    Greasing of Packing

    Is it legal to grease packing before testing a valve? API 598 (section 4.4.1) infers that the packing should not be greased because it is a "sealing surface." Also, MSSP-61 (4.1.2) also says that seat surfaces should be clean. It could be inferred that the packing should also be clean because...
  6. benensky

    Iso dimensioning of holes and shafts

    gearguru - thanks. It was very informative.
  7. benensky

    Iso dimensioning of holes and shafts

    Hg – Sorry to confuse you I just used “X” as a hypothetical or “nonsensical” fit. It looks like you now understand or am I wrong and you need me to give you a new example. Cory – What I was taught was that “nominal” meant the dimension you would like to see the feature made at in a perfect...
  8. benensky

    Iso dimensioning of holes and shafts

    Hg - Because the tolerancing charts say for a 10mm shaft with "X" fit is -2mm/-4mm. Or do you get that and you are just being hypothetical? A point, which I agree with, but some times the determining powers are not correct but have made a decision. A decision which is easier for me live with...
  9. benensky

    Iso dimensioning of holes and shafts

    Kev - Thanks, posted a similar question on the thread you recommended to me. Hg - I wonder the same thing. However I have been drawing to ANSI standards my whole life and accustom to it. For the designers at the European company that is common practice. It may seem odd to us but it is the...
  10. benensky

    Iso dimensioning of holes and shafts

    prohammy - thanks for the links! I understand fits and how that works. What I am asking about is how they are drawn and toleranced on mechanical drawings. For example, if a 1" diameter shaft's fit calls -0.001"/-0.002” I draw the shaft at 0.999" in diameter and tolerance it 0/-0.001". It...
  11. benensky

    Iso dimensioning of holes and shafts

    Cory, Thanks for your reply. I would review those standards if I had them. However I do not and the chances I will be supplied them are pretty slim. That is why I posted here. If you feel my post is inappropereate please let me know and I will not post here any more. -Mike
  12. benensky

    Iso dimensioning of holes and shafts

    Hi, I am new to this forum. Hope you can help me. We were bought by a European company and I work with ISO drawings at times and they tolerance there shafts 10 -2/-4. I have never seen double negative dimensioning. In the USA I was taught that if the fit of a 10unit shaft is -2 to -4 to...
  13. benensky

    Finding Stress in a Round Flat Plate

    unclesyd: flat head on a pressure vessel -benensky
  14. benensky

    Finding Stress in a Round Flat Plate

    I am doing stress calculation on a round flat plate welded to the end of a pipe. So I looked in "Roark's Formulas for Stress & Strain" 6th Edition. I went to chapter 10 “Flat Plates” and checked the examples. In example one (1) they found the largest moment and then plugged that into the...

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