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  1. chris456s

    Bolt checks

    Thanks. F_t,Ed being external loading alone makes sense. "The shear and tensile strengths of a bolt are not affected by the presence of an initial pretension" this is certainly true when bolts are preloaded within their proportional range, as shown by balancing the forces due to preload...
  2. chris456s

    Bolt checks

    ...to preload? The question arises for the following reasons: 1. Notice the tensile resistance check F_t,Ed <= F_t,Rd. Where resistance is K_2*F_ub*A_s/gamma. If Preload is as suggested 0.7F_ub*A_s and K_2 = 0.63 and F_t includes pretension, then the check will always fail under preload alone...
  3. chris456s

    Bolts F_t

    ...to preload? The question arises for the following reasons: 1. Notice the tensile resistance check F_t,Ed <= F_t,Rd. Where resistance is K_2*F_ub*A_s/gamma. If Preload is as suggested 0.7F_ub*A_s and K_2 = 0.63 and F_t includes pretension, then the check will always fail under preload alone...
  4. chris456s

    ASME BPVC Viii.2 4.4.12.2

    In the 2019 ASME BPVC Viii.2,section 4.4.12.2(e) gives allowable compressive stress under axial compressive stress and Hoop Compression. Subsection (e)-1 discusses Fxha for lamda <= 0.15. But subsection (e)-3 also discusses Fxha for lamda <= 0.15. Which one is correct? They seem to condradict.
  5. chris456s

    Vessel Classes

    I only have access to BPVC 2019 and 2015 BPVC.III.2-Annex 3-A 2019 says, for carbon steel in class 1 vessels allowable stresses comes from Sec II, Part D Table 2a and table 5A for class 2 vessels. While 2015 Annex 3-A makes no class distinction and says carbon steel allowable stress comes from...
  6. chris456s

    Y Stress factor without a hub

    In BPVC VIII.2- Section 4.16 Stress listed on Table 4.16.8 for "loose-type flange without a hub" includes a "Y" stress factor. Stress factors for all other types of flanges are listed on tables 4.16.4 and 4.16.5. However, neither of these tables list "loose-type without a hub". Where is the calc...
  7. chris456s

    ASME MAterials

    TGs4...THANKS The guidence in App 46 is exactly what I needed... It is all so very clear now. In fact this clears up other related issues...
  8. chris456s

    ASME MAterials

    Notice how VIII.1 referes to BPVC II Table 1A for Allowable Stresses but BPVC VIII.2 refer to BPVC II table 5A. Many materials (like A-53 and P235) are listed in table 1A but not on Table 5A or on BPVC VIII.2 table 3-A.1....So, A-53 and P235 are suitable materials if you use methods in VIII.1...
  9. chris456s

    ASME Materials

    Thanks for the comments @KevinNZ Using X52. "why use 5L for pressure vessel"....Large diameter 5L pipe is readily available. Often already on site... no need to roll or form. Often seamless, so less welding. Most of my projects are time driven rather than driven by the cost of design and...
  10. chris456s

    ASME Materials

    I have been reading posts regarding an issue I commonly encounter. How to use API-5L pipe or ASTM A694 flanges with ASME codes when ASME VIII and II does not list them? Often the answer is that the ASME just doesn't cover these materials and you can use unlisted stuff provided huge list of...
  11. chris456s

    Friction in Caesar

    ...normal contact with the support and the X direction is free to slide If you want the X direction to have a reaction due to friction (resist sliding up to Fy*Mu) then do you a. assign Mu to X; b. assign Mu to Y; or c. assign Mu to both X and Y? I don't have access to Caesar to test this...
  12. chris456s

    Gasket Seating Area

    ...thanks i have a better understanding now. ASME VIII.1 is for design not actual preload However, 1) A=pi/4 (OD^2-ID^2) is exactly equal to pi*G*w (if w is width) not just approximate. see attached proof 2) If b represents "half width" why does the ASME VIII.1 call it "effective width" and say...
  13. chris456s

    Gasket Seating Area

    ...from B16.20) gasket seating stress, y = Sgt = 26,000 psi (Stainless ring joint BPVC VIII.1 Table 2-5.1) assembly bolt stress Sbsel = (Sgt)(Ag)/(N*Ab) = 72ksi This is 90% of A193 B7m yield...seems high?????? b)If we look at the bolt load calc's using BPVC VIII.1 APP 2-5 ring width, w =...
  14. chris456s

    Autopipe Review

    I have been tasked with reviewing a subcon's autopipe results related to a subsea pipe line I have never used autopipe While reviewing the input files, I found some confusing inputs and cannot get a straight answer. Hoping someone here can clarify Each node in the input file seems to have a...
  15. chris456s

    ASME Sec VIII Pt2 Stress

    thanks for your help. I found my problem. My 2015 version of the code was missing phi in a graphic Like I thought, I was completely misinterpreting what phi was. I looked in a older version and phi was defined in the graphic. It is all so clear...
  16. chris456s

    ASME Sec VIII Pt2 Stress

    Thanks for that But how is this not related to the real world? A location related to tiny phi exists on all items. So how can anyone use this equation? Ignoring small values of phi is like selectively reporting on only locations that have passing values
  17. chris456s

    ASME Sec VIII Pt2 Stress

    I dont think you understand what I am saying I am not describing a small attachment phi is a location according to the Nomenclature section. So even a huge attachment can have location on it ranging from phi = 0 to phi = 360 deg So if I choose a very small phi...like 0.00001 degrees from what...
  18. chris456s

    ASME Sec VIII Pt2 Stress

    In BPVC Sec VIII pt 2 paragraph 4.3.10.2, the middle term for stress sigma_sm for spherical shells has a sin squared phi in the denominator. Phi is listed as a spherical location in the Nomenclature section. So for infinitesimal values of phi, the stress on externally loaded spherical shell...
  19. chris456s

    STAAD Pro Report

    I'm using STAAD PRo V8i (Select Series 4) I have a frame structure made of tubular members with an API code check The API code check assesses the tubulars to API RP 2A section 3 and assesses joints to API RP 2A Section 4 The results of both the Section 3 and Section 4 checks are presented in...
  20. chris456s

    Wave loads

    Is there a way to assign more than 4 wave conditions? My wave loads page seems to be limited to 4.

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