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  1. NovaStark

    Inconel overlay for tubesheet in hydrogen service

    It will depend on your material of construction, the hydrogen partial pressure and temperature. In most cases those overlays are to provide a barrier between the hydrogen and the steel to preven high temperature hydrogen attack. You can reference the Nelson curves in API 941.
  2. NovaStark

    18 " weld neck flange weld joint repair

    If it is actually water seeping out, there are wraps like A+ that can be verified via ASME PCC-2 that an experienced leak sealing company can install for you. Of course these tend to require some degree of surface preparation and as LI says, you can run the risk of making the leak worse. In...
  3. NovaStark

    CAESAR SIF Question

    From the C2 Quick Reference under the What's New section Once you have V13 and later, it appears it would use B31J. Before that it would be via App D and the B31J tool if installed.
  4. NovaStark

    Old Boiler Steam Drum and Mud Drum material

    Are you able to extract a sample of the material for testing purposes or able to perform PMI on the material ? Otherwise, you may need to be very conservative in what you material you are assuming as it is essentially a best guess. If the name plate is still on it, you may be able to get a...
  5. NovaStark

    Thick wall / high pressure pipe wall thickness calculations

    The formula stated in the code of t = PD/2(SE+PY) is used assuming the pipe is thin such that t < D/6. If you have a situation where t>= D/6 or P/SE >0.385 then you won't be able to use the above equation as the basis is not a thin pipe anymore. At that point, you would be likely needing to do...
  6. NovaStark

    Calculation for change Weldolet with pipe to pipe

    I can't rememeber the exact paragraph in B31.3, but those integrally reinforced branch welded fittings are typically expempted from the calculatons once they adhere to some additional criteria. If you wish to change the type, then you'd need to redo the branch reinforcement calculations and...
  7. NovaStark

    Safety Valves for Pressure Vessels and Heat Exchangers

    Do you have any previous inspection history for the valves ? Depending on the service and operational history you may find that those in clean service may not require frequency internal inspection and recertification. However, those in dirty service may. Some valves such as those on boilers...
  8. NovaStark

    Code calculations to determine the thickness of the flat plate to blank leaking tubes

    Hello Gears6580, Are you referring to welding a flat plate onto the tubesheet where the tube is being extracted ? You can consider putting a tapered plug of suitable dimensions as that may be easier depending on the configuration. UG-34 would generally be the way to go once you select the...
  9. NovaStark

    Stress analysis - Strange thing

    Do you have the details on how the external engineer modelled the anchor on the condenser ? Are the loads on the rest of the piping comparable or do you have case of lift-off occurring and thus causing more loads to be transferred towards the anchor ? Are the allowable loads on the condenser...
  10. NovaStark

    Need review for pipe wall thickness calculation sheet for pipes under internal pressure

    One thing you can do with these types of spreadsheets, is to manually calculate one of the thickenesses. If your answers match (within reason due to rounding), then you know your formulas are correct. When I had to do these types of repeated excel calculations with more complicated formulas...
  11. NovaStark

    Applying torsional moment to shell/support in PVElite

    I am not sure there is a specific way to do that on a shell. AFAIK, the force/moments are calculated based on WRC107/537 which are really for the local effects of the attachment on the nozzle/shell. You may need to reach out to Hexagon for further advice.
  12. NovaStark

    High Temperature Pipe Stress

    Your best bet may be to improve the metallurgy. You can also look into increasing the pipe thickness however that can only get you so far. Did your stress model pass the EXP load case ? At one of the facilities that I have worked at, there were 304H SS piping designed to 1200 degF. However...
  13. NovaStark

    Flash vessel control valves

    @Abhijeet242 These are quite large pipe sizes. What flow rate and DP are you looking at? Depening on these, you will need stellit trims as georgeverghese suggested but also you can possibly run into steam erosion problems in the piping itself. Noise can also be a factor as well (maybe you...
  14. NovaStark

    Derating of process piping designed to ASME B31.3

    The first thing to do is to properly define the problem to ensure that the correct engineering solution is being applied - or at the very least, to understand the root causes of the issue(s) being faced. If de-rating is necessary, you should have a comprehensive assessment with your process...
  15. NovaStark

    Thermography to survey pipe internal wall loss

    You'd have too many unknowns and like EdStainless suggests, unless you have some specific way to calibrate against a known standard, you're mostly going to be guessing. Depending on the process fluid and temperature, wall profile radiography might give some useful results.
  16. NovaStark

    Design Temperature -In service repair /Modification

    @deepu78 The design temperature is most likely based on a factor of the maximum operating temperature of the system. The piping specification would thus likely be based on components with thicknesses/materials to withstand at least 450 degC. I would think that if you install something that is...
  17. NovaStark

    Piping Stress Analysis Questions

    There are some codes that specify that the hot modulus Eh can be used for equipment nozzle loads given that Ec may be too conservative. So it depends on what you are doing and how sensitive your results at a particular location.
  18. NovaStark

    PCC-2 Fillet Patches Clarifications

    As this would be essentially a type B sleeve in PCC-2, any particular reason why ?
  19. NovaStark

    PCC-2 Fillet Patches Clarifications

    With respect to a full circumferential ring, wouldn't the analysis to determine the thickness of the ring end up including the eccentricity check i.e. bending resulting in the same thickness of a fillet patch ?
  20. NovaStark

    How header pipe surface crack, after 5 years later on the Weldolet Weld Finish Area

    @OP Do you have any other information about the line or has your investigation determined it to be due to the welding ?

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