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Recent content by enrjdean

  1. enrjdean

    Heat transfer over time in a rubber pipe

    Hi Ione I had looked at Newton's law of cooling, but couldn't put the steps together that you guys were trying to get across. I've plugged some numbers into the equation and am starting to make a bit more sense of it; thanks for sticking with me!! The large value ok K I can only assume is due...
  2. enrjdean

    Heat transfer over time in a rubber pipe

    Prex ok, so the oil disaptes heat (in this case power, Watts) through the wall of the pipe which has some conductivity (k). 1 watt = Joules/sec. So through iteration I can find what the total time it would take to drop to sea temp. I hope I have followed your notes correctly. I have attahced...
  3. enrjdean

    Heat transfer over time in a rubber pipe

    Hi Ione Thanks for your response. I assume by using the control volume this will give me the rate in sec's per sqm due to temp drop. Multiplying this over the length of the pipe will give me the total time over the whole length?
  4. enrjdean

    Heat transfer over time in a rubber pipe

    Hi guys attahced is the spreadhseet I have made up with the above equations, thanks! One question tho, I have calculated the mass of the contents sitting in the pipe and assume that the pipe is full. What is meant by "crude oil mass in a length of pipe having 1 square external area"? Do you...
  5. enrjdean

    Heat transfer over time in a rubber pipe

    Hi Sorry for the mix up in units, will post the correct ones tomorrow. Is also 6000m^3/hr. I assume that the fluid is left in the pipe and that the pipe is full. So using (k) thermal_cond*delta_T/thickness I get a heat transfer rate, Watts. What I really need is to get to the answer in...
  6. enrjdean

    Heat transfer over time in a rubber pipe

    Hi I haven't had any hits on the search regarding this particular topic, if they are there, I appologise. I'm having trouble calculating the following: 20" rubber pipe submerged in sea water at 27-28C has had crude running through it at 6000m^3. The crude, has been pumped at around 65C. The...
  7. enrjdean

    Parameters from features in Cosmos

    Hi I'm having trouble creating a design scenario in solidworks. The parameter I'm trying to varie in the study is from an extruded feature and is coloured blue, hence it won't select or let me drive this dimension as a parameter. Anyone got any ideas on how to solve this? Kind regards Jim
  8. enrjdean

    BS1501 - 161/151 grade 400A

    Hi Can anyone please explain the designation of: BS1501 - 151/161 grade 400A? What does the 151/161 stand for? Regards Jim
  9. enrjdean

    ASME 16.5 Pressure/Temp FS

    Thanks TGS4 I did perform some calculations to look at the bending moment, axial stress and also a surge presure seperately, but only on the pipe section of the flange (welded kneck type). Under the conditions I specified this gave me a 1.75 FS, but only on the pipe section. To be honest, I'm...
  10. enrjdean

    ASME 16.5 Pressure/Temp FS

    Hi guys Heres the background to the problem. I have a hose connected to a rigid pipe by two 20" CL300 flanges. There is a 310kNm bending moment on the hose with also an axial load of 600kN. I have worked this into an 'equivalent pressure' using the formulae: Peq = 16*M/Pi*G^3 + 4*F/Pi*G^2...
  11. enrjdean

    ASME 16.5 Pressure/Temp FS

    Hi, can anyone tell me what Factor of safety is used within the pressure temp ratings in ASME b16.5? For example, a cold rated CL300 carbon steel flange is rated at 51.1bar, but what is the attached factor of safety involved? I have seen pressure tests with hoses using these flanges at well...
  12. enrjdean

    Pressure drop of gas in a pipe line

    BigInch I've been reading through the PDF that you posted which shows different examples and equations that are used for calculating the pressure drops/flow rates ect of a compressible fluid. These examples use a effiency factor of a pipe (E) and also a compressibility factor (Z). The...
  13. enrjdean

    Pressure drop of gas in a pipe line

    Mr. Montemayor Thanks for the spreadsheet, much appreciated! Rather than blindly plug my values into it, I'm trying to work through the sheet so I can gain a better understanding of whats going on with the calculations. However, theres a few constants croping up, that I can only guess at what...
  14. enrjdean

    Pressure drop of gas in a pipe line

    Thanks Katmar, much appreciated! Jim

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