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 sbnz

  1. sbnz

    longitudinal stress in pipe under internal pressure

    Thanks BigInch - you have confirmed what I thought, but had slight doubt to seek for a 2nd opinion. I am aware of the main and intermediate anchors across the exp joints and have taken care of the pressure thrusts accordingly. Was just unsure if the intermediate pipe still has any longitudinal...
  2. sbnz

    longitudinal stress in pipe under internal pressure

    Of course, the longitudinal (meridional) stress exists in pipe under internal pressure. It is to counteract the pressure thrust that acts at the ends (pipe closures) or direction changes (i.e., bends). In magnitude, it is 1/2 of hoop stress or (hoop= Pr/t, longitudinal = Pr/2t)
  3. sbnz

    longitudinal stress in pipe under internal pressure

    Hi, An elementary question for the experts. For piping under internal pressure, the longitudinal stress in pipe elements is the sum of a) stresses due to bending and b)longitudinal (or meridional) stress due to pressure ( pD/4t) Question is, for a section of piping within 2 expansion joints...
  4. sbnz

    Mollier diagram of steam - SI unit

    great - thanks heaps quark
  5. sbnz

    Mollier diagram of steam - SI unit

    No - this is good. Thanks Don't know how I missed this cheers
  6. sbnz

    Mollier diagram of steam - SI unit

    Hi, Could somebody suggest a link for printable mollier chart for steam in SI units please? My google results have not been very satisfactory yet - I am getting diarams either in imperial units or poor image quality thanks in advance
  7. sbnz

    Safety shut-dwon of wellheads

    Hi, I have received a concern (from environment specialist) during a Hazop analysis for a steamfield that what is the safety provision in the (unlikely) event of the two-phase or brine cross country pipeline rupturing (say, hit by a heavy truck) Admitting this is improbable to "break" a...
  8. sbnz

    Set pressure of safety valve

    Very interesting discussion. Thanks ekschaw for sharing your observation. gmax137 - you said you have seen similar design (pipe design pressure lower than (at least one) safety valve in the line). Would you please share further which line (steam?) and in what type of plants have you seen that...
  9. sbnz

    Edit Add-In and userined function (.xla)

    Hi, I have been using a .xla file in the xlstart folder for a long time (originally sourced early during my career) which contains various useful custom built functions for my area of work. I can access the functions built in the .xla file perfectly from within Excel in my computer (under...
  10. sbnz

    50NPS Cast steel valve rating

    Quick question : Do Cl-150 and Cl-300 rating valves exist for small sizes of 25 and 50 NPS (1" and 2") - or is it minimum Cl-800? cheers,
  11. sbnz

    Fabricated slip-on flange

    11echo - interesting to note your practice. May be it is ok in refinery piping design In power stations, for high pressure piping as per code, that would not be acceptable though. The SO flange thickness is higher than the blind thickness and need to be full hub thickness for fabricated flange...
  12. sbnz

    Fabricated slip-on flange

    How do I calculate the thickness (and other requirements) of a fabricated (from plate) slip-on flange, to comply with piping code (B31.1) requirements For specific reason, we can not use a standard Cl-900 flange to B16.5 in this particular case and need a special flange made. thanks
  13. sbnz

    Pressure pipe design - thermal stress range

    Hi, What is the exact definition of "thermal stress range" in pressure piping codes B 31.1 or B 31.3? Does it mean: a) the thermal stress range from "installation" temperature to either maximum or minimum operating temperature, Or b) the thermal stress range from "minimum" to "maximum"...
  14. sbnz

    load combination for piping analysis

    For a pressure piping system in a power plant that we are designing as per B 31.1, the combination of maximum operating plus occassional (cyclonic wind) loads are resulting in excessive nozzle loads for connected equipment. Is it reasonable to assume a less severe combination (eg, wind loads...
  15. sbnz

    drop down combo list

    Thanks heaps Clyde You are right - it is not an ActiveX control, but one of the forms that can be used from the "Forms" toolbar. It looks so easy and obvious once you know the answer - I was struggling for hours to figure out the object type unsuccessfully. cheers,

Part and Inventory Search