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  1. loilfan

    B16.5 Flange Surpasses App. 2

    Thanks SnTMan. The result is still quite surprising to me, but it was a good exercise! Did your calculations use the Bolt spacing factor Bsc?
  2. loilfan

    B16.5 Flange Surpasses App. 2

    SnTMan, agreed, I couldn't find any discussion about people passing B16.5 flanges by such a margin in App. 2, just discussions about failing them. I used a standard A105 B16.5 150# RFWN with the additional info: Bore 5.761" for Sch 80 Gasket OD 8.25" Gasket ID 7.1875" Raised face 0.06" Hub...
  3. loilfan

    B16.5 Flange Surpasses App. 2

    Hello everyone, Has anyone checked a B16.5 RFWN flange against VIII-1 App. 2 and had it pass at a pressure much higher than what B16.5 permits? We have an NPS 6, Sch 80, A105, RFWN with A193 B7 bolts and a gasket with m=3 and y=9,000. Per B16.5, this is rated for up to 285 psig. Using App...
  4. loilfan

    B31.1 Hydrotesting with Blind Flanges

    In B31.3 345.2.3 (b) Flanged Joints it says: "Flanged joints used to connect piping components and subassemblies that have previously been tested, and flanged joints at which a blank or blind is used to isolate equipment or other piping during a test, need not be leak tested in accordance with...
  5. loilfan

    When is a PSV required?

    In Alberta, Canada, our jurisdiction (ABSA) has given rules for registering a system that is OPPSD (Overpressure Protection by System Design). See AB-525 for more info. This of course is only Alberta-specific, but it shows what we do here.
  6. loilfan

    Fire Case Unwetted Surface Area - Vessel Top Head

    For an open pool fire on a vertical, uninsulated, air-filled vessel do you include the full area of the top head (ellipsoidal) when determining the unwetted surface area? It's at ground level and is less than 25' tall. I have a few different sized vessels between 8' to 12' diameter. Since the...
  7. loilfan

    PG-71.5

    I only have the 2002, 5th edition of API 526 but I don't see it mentioning weld necks. Was it added to the latest edition? For ASME VIII-1 PSVs, does that mean that any inlet piping greater than Sch STD with the same NPS would be a restriction?
  8. loilfan

    PG-71.5

    don1980, B16.5 does list the minimum Bore for flanges. There are three columns (Slip-On, Lapped, and WN/Socket) all with different values. We can't use the columns for Slip-On or Lapped Flanges because their bores are larger than the OD of the pipe. Note 7 of Table II-8 (150# Flanges) says...
  9. loilfan

    PG-71.5

    LatexMan, 150 psig. What does the set pressure have to do with the inlet required area? don1980, thank you for the interpretation reference. Unfortunately I don't see how to use that. The way I understand it is that the valve inlet area is the diameter where Pv is written in Figure 8 of API...
  10. loilfan

    PG-71.5

    This requirement is still odd to me. Let me explain why: In my example above, let's assume I have Sch 80 pipes and that my nozzle connection is now 2" instead of 2.5". The 1.5" pipes attached to each PSV has a combined area of inlet connections of 2*PI/4*1.5^2 = 1.125PIin^2. The nozzle...
  11. loilfan

    PG-71.5

    PG-71.5 of ASME I says: "When a boiler is fitted with two or more pressure relief valves on one connection, this connection to the boiler shall have a cross-sectional area not less than the combined areas of inlet connections of all the pressure relief valves with which it connects and shall...
  12. loilfan

    Multiple Nozzle Openings Overlap

    Thanks for the responses everyone. Without the explicit wording the Code, it's nice to have the opinion of others within this community to make sure I'm not misusing the intent of the Code.
  13. loilfan

    Multiple Nozzle Openings Overlap

    Thanks for the response metengr. Figure PG-38.1-1 is identical to Figure UG-42(a). I forgot to mention that my question is relative to ASME VIII-1. I didn't see anything else in PG-38 or PG-33 that further clarified my question. Unless there's something I missed, I'll keep my question...
  14. loilfan

    Multiple Nozzle Openings Overlap

    I have two openings close enough together that their limits of reinforcement overlap. One of the nozzles (N1) is a forged HB type and has sufficient reinforcement in the area A2 to pass. The other nozzle (N2) needs A1 and A2 reinforcement to pass. Am I able to "ignore" the A1 area for N1...
  15. loilfan

    UG-36(c)(3)(-b)

    Thanks SnTMan. I missed those definitions at the start too. I had looked in Appendix 3 instead.
  16. loilfan

    UG-36(c)(3)(-b)

    UG-36(3)(c)(b) permits an opening up to 2 3/8" diameter provided it is a threaded connection. An untapped hole would only be stronger than a tapped hole provided no additional strength is claimed from the additional threaded component. The finished diameter would only be bigger with a tapped...
  17. loilfan

    UG-36(c)(3)(-b)

    david339933, thanks for pointing out Table UG-43. That should be used instead of the values in B1.20.1 or B16.11. I edited my earlier post. Per the definitions of threaded, studded and expanded connections in UG-43 (d) to (f), we can conclude that UG-36(3)(c)(b) applies for tapped holes...
  18. loilfan

    UG-36(c)(3)(-b)

    Thanks for sharing your work, rww88! I take "studded connection" to mean something like this link where the vessel wall has sufficient thickness for the minimum thread engagement of the bolts. One could argue that it is a welded connection and would instead fall under UG-36(c)(3)(a)...
  19. loilfan

    UG-36(c)(3)(-b)

    SnTMan, the wording in the Code doesn't distinguish the opening as tapped or un-tapped, which is essentially the basis of my question and a better way to frame it. To make this all easier, I'll re-write my question as: does UG-36(3)(c)(b) apply to un-tapped holes? If it's a tapped hole or...
  20. loilfan

    UG-36(c)(3)(-b)

    We are looking to modify a pressure vessel so that it has a finished opening 1 7/8" diameter in a 3/8" plate. A pad is placed on the inside of the shell and is threaded in place by a threaded flex hose hooked up to the nozzle. The opening will not be near any discontinuities or welded joints...

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