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Recent content by georgeverghese

  1. georgeverghese

    API 676 MULTIPHASE PUMP MOC & NPSH

    Disappointment and chaos waiting in the wings in this rainforest - screw type MPP with solids in the feed. Good luck to your project managers.
  2. georgeverghese

    Allowable Overpressure for Electric Steam Boilers per ISO-4126

    If your exit piping is short and developed backpressure is < 10% of PSV set press, then also apply a max permissible exit velocity of 0.5Mach
  3. georgeverghese

    EPC Contractor Needed – Gas Compressor Revamp & Gas-Lift System Upgrades (20+ yr-old Unit)

    Since you plan to move from oil seals to dry gas seals on K303, and given the low mol weight gas service requirement, it is most likely new compressors will be required to operate with the existing GTs' for these machines. Compressor rotor fouling may require changeout of demisting devices on...
  4. georgeverghese

    Foam Glass Insulation - fire case

    See the footnotes on that F factor table in API 521- will your foam glass insulation remain intact with high velocity fire hose jet stream ? If not, go for this insulation which is typically used in the oil/ gas business to enable taking full credit for its insulation during a pool fire ...
  5. georgeverghese

    Bernouilli in vertical pipes

    If the exit is in free air, then the downcomer will be in 2 phase air / water flow
  6. georgeverghese

    Bernouilli in vertical pipes

    At point 2, is the exit in free air or is it always dipped in the water ?
  7. georgeverghese

    Axial Control Valve Sizing

    Agreed, at max flow, P2 may be 36barg, while P1 may be 36+x barg, where x is the dp relevant for this max Cv case. Note that in some services, for the max Cv case, it would be acceptable for calculated Cv to be < say 0.75x wide open Cv, while in other operating cases, it may be acceptable for...
  8. georgeverghese

    Axial Control Valve Sizing

    Those values are probably the range of pressures for P1 and P2. This info you've presented is clearly not the sizing info. There should be 2 design cases for control valves: a) Flow with P1/T1 and P2 /T2 which leads to max Cv b) Min flow with P1 / T1 and P2 / T2 which leads to min operable Cv...
  9. georgeverghese

    Confined Flame in a Cylindrical Furnace for Glass Melting

    Think there is an error in that writeup - the inner glass liner of 72mm dia is not 1000mm height. It is the outer 90mm glass liner, which forms the base of the cylindrical insulation, which is 1000mm. Height of the 72mm inner liner is not stated, but is shown to be much less than 1000mm looking...
  10. georgeverghese

    Does dry gas PSV always need drainage on discharge pipe ?

    This document may be useful as a checklist https://www.eiga.eu/uploads/documents/DOC211.pdf This std also recommends a min design pressure of 40barg (class 300 ) for the vent pipe to withstand detonation, and this would include the PSV also. Note it doesnt suggest the use of this toroidal...
  11. georgeverghese

    Valve at inlet side of pump

    Valves installed at the bottom of the suction pipe for pumps are not a good idea - they tend to bung up with debris/ corrosion products over time, and the valve will not close. Preferred orientation is vertical downward movement to close.
  12. georgeverghese

    Does dry gas PSV always need drainage on discharge pipe ?

    You may most likely have to purge this PSV exit line with N2 to prevent flashback / detonation for this highly flammable H2. Purging this line with N2 is much preferred to installing a flame arrestor / detonation arrestor which is often prone to blockage. N2 flowrate should enable a line...
  13. georgeverghese

    Does dry gas PSV always need drainage on discharge pipe ?

    And what would happen if this dryer was completely deactivated / poisoned, and the dewpoint analyser was not working - what would dewpoint be then leaving this PSV?
  14. georgeverghese

    Heat Exchanger UA value - Query

    @TiCl4, Modelling of heat exchangers in turndown with UA held constant as an approximation, enables the derivation of new terminal temperatures leaving the HX, albeit at a lower heat transfer duty, which then has some effect on downstream units.
  15. georgeverghese

    Piping for N2

    If flows are small, you can choose between copper or SS316 tubing. If flow requires piping, SS316 would be better to avoid external corrosion over the long term, especially in damp ambient conditions, or when piping runs through difficult to access areas and/ or when it runs along with many...

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