Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. CJKruger

    Liquid flow through a vapor trim PSV?

    hniaboujemaa, thanks for a very interesting reply. Two curiosity questions: 1) Do you know if your last sentence (non-cert liq eqns for vapor trim) is actually written down in a standard ? 2) What about liquid certified valves with a vapour relief case ? Are the normal vapour phase equations...
  2. CJKruger

    forced circulation reboiler percent % vaporization

    cheme89, you can probably assume it is similar to a forced circulation fired heater which is typically design for 50 wt% vaporization.
  3. CJKruger

    VDU ejector off gas

    Milutin, some companies put it to a flare header. The Flare Gas Recovery system is then used to send it to an amine unit. Several risk though (like air into your flare system).
  4. CJKruger

    Open discharge system: Pressure value at point of discharge??

    zdas, this is a very strange explanation of choked flow. Some proof is needed before this explanation can be regarded as correct. I think what really happens is much simpler. Taking your example of 10,000 psig PSV discharging into 50 ft of 2-inch pipe: (a) If the PSV nozzle area is very small...
  5. CJKruger

    Rated vs Actual vs Design rate ?

    Rated flow = Design flow * (Full open area / Design area). Sequence of calculations are as follows: - Calc required relief flow from scenarios (design flow). - Calc design orifice area from design flow. - Select a standard relief valve with full open area larger than design area. - Calc rated...
  6. CJKruger

    Rated vs Actual vs Design rate ?

    Okay, let me take a stab at it: Design = Required flow rate from your relief scenarios. Rated = Certified flow rate based on full open valve. Max = 1.1 times Rated flow (as ASME derate by 10%). "Actual" I assume is whatever happens in a real relief case.
  7. CJKruger

    Open discharge system: Pressure value at point of discharge??

    jamesbanda, yes it is atmospheric pressure except if the pipe chokes at the outlet.
  8. CJKruger

    Back pressure 3 %/ outlet loss 10% guage or absolute

    Gauge pressure (not absolute).
  9. CJKruger

    Compressible Flow Idiot

    KernOily, With Excel the easiest way is probably as follows: - Calculate the mass flow rate using the isothermal compressible equation for a range of pipe outlet pressure (say from Pin to close to zero). - This is a simple calc that is not iterative (except for f maybe) and depends on the pipe...
  10. CJKruger

    Compressible Flow Idiot

    ione, 2) No, you can (and usually do) have a shock wave by simply going to sonic flow (assuming adiabatic). No need to go supersonic to get a shock wave. Cilliers
  11. CJKruger

    Compressible Flow Idiot

    KernOily, 1) Partly. If you increase upstream pres (at fixed downstream) then the flow will eventually choke at the pipe outlet. If you continue to increase upstream pres, the mass flow will increase, but the flow will remain choked at the pipe outlet. 2) Partly. The flow will never go...
  12. CJKruger

    Compressible Flow Idiot

    KernOily, download the trail version of Korf Hydraulics from www.korf.co.uk and use it to solve this problem. Email me if you are interested in the equations used in the program. Cilliers (please note I am involved with Korf).
  13. CJKruger

    Reducer In Relief valve inlet line- Pressure Loss

    I agree with sheiko, just use non-recoverable pressure drop. Cilliers
  14. CJKruger

    PSV for steam generator

    dubulu123, the superheater PSV cannot be deleted as it is mandatory per ASME I (PG-68.1, and 67.1 in your case). Cilliers
  15. CJKruger

    What sould be Angle of FT taping for Liquid Service

    For liquid hydrocarbon service my preference is 45 deg up. Mostly to prevent water settling in the legs. Cilliers
  16. CJKruger

    Estimating flow depth in partially filled pipe.

    robche, if it is gravity flow, try the Manning equation.
  17. CJKruger

    PSV sizing for glycol cooler

    processengineer1998, in general I agree with the comments made by CMA010. Two other points: - Do you need a relief valve just for the exhanger ? If you only have a fire case here, you may be able to rely on a relief valve on a connected vessel (see AMSE 8 Appendix M). - For hydrocarbons we...
  18. CJKruger

    Siphon Break Question

    sshep, I think the vent line can only break the siphon once the level drops below the vent line tie point. 1) So, overflow will start when the drum water level is above the 180 bend, and stop when the level drop below the vent tie point. 2) This assumes the overflow pipe is fairly small. If...
  19. CJKruger

    Pipephase loop network model does not solve

    adam89, if all else fails, try a tool that will converge for this system :-) Such as Korf Hydraulics at www.korf.co.uk (please note that I am involved with it).
  20. CJKruger

    Heat loss from a pipe in the wind

    sshep, historically many companies used the modified Langmuir equation. It was also used in the 1995 version of ASTM C680, but I seem to recall there are typo's in this standard. I think newer versions of this standard use a more modern equation, but I still use the Langmuir equation.

Part and Inventory Search

Back
Top