Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by MBlackman

  1. MBlackman

    Factors in NC-3658.3

    Calculator with auto-lookup of data here, in case it helps https://stressandintegrity.com/app/index.lc/ASMEIII https://stressandintegrity.com Articles & web apps for stress / integrity engineers
  2. MBlackman

    stress classification and FSRF for thermal stratification

    Thanks very much for your response TGS4. I will treat it as a principal stress (not shear) and apply the FSRF. I note that API 579-1 2016 also has the option of separating out local thermal stress and not applying the FSRF (ref. Table 14-4), but it appears not to be the appropriate stress...
  3. MBlackman

    stress classification and FSRF for thermal stratification

    I am talking of Sect 5.5.3.2 STEP 4, eq. 5.30 and the note (a) below.
  4. MBlackman

    stress classification and FSRF for thermal stratification

    I'd like to hear your opinion on classification of repeated thermal stratification for fatigue assessment using the smooth bar curve. Hot/cold liquid stratification, or a half-filled horizontal cylinder can cause both thermal bowing and localized thermal stress at the level where an abrupt...
  5. MBlackman

    coating for bare pipe at supports

    Posted this on a Linkedin group, no response so trying here. According to one article from a pipe support vendor, corrosion under bare carbon steel pipe at resting supports is initiated when the coating degrades from sitting in contact with trapped moisture for long periods. So even when resting...
  6. MBlackman

    45 degree latrolets...some questions

    Jaydee Use the appropriate fitting and wall thicknesses as designated by your pipe spec. Heavy wall thicknesses are often specified for small bore piping for mechanical strength reasons rather than pressure capacity. Presuming Sch160 is specified for your 1" piping, the appropriate fitting...
  7. MBlackman

    ASME BFJ

    Thanks jt, based on various literature I've come across there is a new(ish) draft method for design of flanged joints and tightness prediction, which as I understand is intended to form a new non-mandatory appendix. (PCC-1 is specifically for assembly to my knowledge). I've seen this referred to...
  8. MBlackman

    ASME BFJ

    Where can one find a copy of the draft ASME rules for Bolted Flange Joints ?
  9. MBlackman

    No ASTM A420-WPL6 or ASTM A234-WPB in CAESAR II Materials Database

    Are you sure the warning wasn't preceeded by 'if the bend is bent pipe' ?...as we all know listed components such as elbows to B16.9 don't need to follow the code equation for bends, and you don't really know what thickness they are other than at the ends anyway.
  10. MBlackman

    high pressure piping and Bourdon effect

    I think you are justified in running the analysis with pressure elongation switched on and using the maximum operating pressure rather than design pressure (for nozzle loads only), and running it with design pressure for the stress check.
  11. MBlackman

    RhoV2 criteria for Line Sizing

    Rho-v^2 'at-caution' limit of 200000 kg/ms2 is recommended in NORSOK P-001 for gas relief & blowdown piping. Note that the dynamic load imposed at a change in direction is proportional to Rho-v^2.D^2
  12. MBlackman

    Local peak stresses in solid models

    Also check out the SOLID 186 20-node element. You should use two elements in the through thickness direction. There is a WRC bulletin 429 that recommends that it is inappropriate to consider calculated stresses in sharp transition regions, as for one thing it is considered very unlikely that...
  13. MBlackman

    Surge Loads in Pipework

    BigInch I agree with your point below, either I didn't make myself clear or you have read something unintended into my statement. The point I was making is that while the total load on a support may be increased, it is not due to the driving force (surge pressure) increasing, but is due to the...
  14. MBlackman

    Surge Loads in Pipework

    DSB123, The short answer is that a DLF should not be applied to the restraint loads reported by a time history analysis. The tricky bit is ensuring that you've got the time profile of the surge pressures correct and of course that your system is realistically modelled. You can easily see for...

Part and Inventory Search