Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations pierreick 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 GD2

  1. GD2

    Pipe Wall Thickness Calculation - EN 13480 Part 3

    Sorry, I am not used to EN standard. I am an ASME guy. I can’t therefore validate your strength numbers. As for creep, it is when the material time-dependent properties kicks-in. Examples are heater tubes where the tubes has to be designed for both elastic and rupture (creep). If you haven’t...
  2. GD2

    Pipe Wall Thickness Calculation - EN 13480 Part 3

    Why do you even have to do the time-dependent evaluation? CS @204 C will never cross to the creep regime. Temperature limit to define the creep range for EN 10217-2 Gr P235GH material will be 343C-371C depending on the reported tensile strength.
  3. GD2

    Minimum pipe length for Process Vent

    There is no standard available. You have to make one for your company or the project. Process vent should be a proper vent assembly with valves that will be used for the life cycle of the plant during start up, shutdown, maintenance etc. It should be based on the piping class. Different vent...
  4. GD2

    B16.5 Max Flange Hydrostatic Test Pressure

    If I am reading/interpreting B16.5 P8.2.2 correctly, CL150 reads 20 bar (290 PSI) at 38C X1.5 =30 bar (435PSI) max flange pressure. Or would it be 21 bar? The test pressure would be 450 psig rounding off to next higher 25 psig. It's the max test pressure. However, note that you won't be only...
  5. GD2

    B16.5 Max Flange Hydrostatic Test Pressure

    You don't have to break your head. Instead you need to read ASME B16.5 Para 8. Flange test pressure is 1.5x the pressure rating (MAWP) at 38C given in Tables 2-1.1 or Table II-2-1.1 rounded off to next higher 1 bar or 25 psi.
  6. GD2

    Pressure variance on diameter

    What's your pump make and model?
  7. GD2

    Differences in Minimum Allowable Stresses in ASME B31.3 for Low and High Pressure

    You are right. For t<D/6, the Lame's equation for thickness calculation becomes overly conservative. The stress across the wall thickness is no more assumed as membrane (equal) and varies across the wall. That's where the base code and high pressure fluid system Chapter IX kicks in. If you...
  8. GD2

    API 579 FFS-1 general / local metal thinning case study

    Grid option is preferable for both because if the PTR produces COV >10%, grid is required anyway.
  9. GD2

    off spec piping

    Why do you say the nozzle has to be from a pipe? As long as it meets the acceptable material by the Code, it can be fabricated by other methods too.
  10. GD2

    Settlement of Oil Pipeline due to Leakage of Water Pipeline.

    How about the possibility of a clamp over the coupling, injecting with sealant, with tapping to a surface vault to monitor the joint pressure and inject with fresh sealant when required.
  11. GD2

    Pressure increase as diameter increases

    Looks like 110 psi discharge pressure meets your system requirement. Look for a pump with TDH 114 psi (as Katmar had said) and 200 GPM near to the Best Efficiency Point (BEP) on the pump Characteristics curve (H-Q Curve). if you are little skeptical, you can increase to say 120 psi (you can...
  12. GD2

    Pipe wall thickness sizing

    The Safety valve is set at 290 Barg which is equal to the MAWP or Design Pressure of the Pump. Pump manufacturer has set it based on the design of the pump. For the piping, you need to first determine what should be the design pressure. This will be based on the MOP you need. If the PRV had...
  13. GD2

    How to Manage Pipe Support Lift-Off in Stress Analysis

    Typically Max Operating Temperature will be 240C ( a 10C margin with Design temp). Will it make any difference to your stress result? If you have overhead space, a long rigid spring hanger instead of variable might work.
  14. GD2

    SA-182 VS SA-965 for heat exchanger tubesheets and girth flanges

    It will be incomplete to comment without the process in play. The process will typically decide on the material selection like Krausen said. Once the material is selected, you see whether it can be resourced easily and local fabrication expertise is available. If not, you go the next material in...
  15. GD2

    Gas Pipeline Reversal

    Other things to look at: Perform major reviews of the pipeline’s condition and history, including: • Laterals and connections • Piggability and line cleanliness • Right-of-way conditions • Existing threats, such as corrosion or mechanical damage • Potential threats, such as fatigue •...

Part and Inventory Search