Calculation of Beta Ratio - Intergraph Smart Instrumentation - 13.1 - Reference - Hexagon PPM

Integraph Smart Instrumentation Sizing Equations

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Reference
Smart Instrumentation Version
13.1
  1. Calculate internal pipe diameter at flow temperature:

  2. Calculate correction factor for steam quality (for liquid, water, and steam, Fs=1):

  3. Calculate scale reading factor:

  4. Calculate differential pressure at normal flow rate:

  5. Calculate pipe Reynolds number at normal flow rate:

  6. Checking for critical flow.

    1. Liquid/Water case:

      1. If then the flow is critical.

    2. Gas/Steam case:

      1. For Venturi tubes:

      2. For other restriction devices:

      3. Calculate critical pressure ratio and define whether the flow is crtiical:

        If then the flow is critical. If not, the flow is sub-critical.

  7. Calculate b - ratio.

    Case A Liquid/Water - critical flow

    1. Calculate DP.

    2. Calculate first estimate for b - ratio.

      For Venturi tubes:

      For other restriction devices:

    3. Eps=1.

    4. Calculate discharge coefficient. See the Appendix.

    5. Calculate the new b - ratio.

    6. Calculate the relative change in b - ratio.

    7. Repeat steps d to f until the relative change in b - ratio is less than 0.0001.

Case B Gas/Steam - critical flow

  1. Calculate gas expansion factor:

  2. Calculate discharge coefficient. See the Appendix.

  3. Calculate first estimate for b -ratio (Wn[1b/h], T[r], P1{psi-a}, D[in]:

  4. Calculate orifice diameter at flow temperature:

  5. Calculate bore Reynolds number at normal flow rate:

  6. Calculate discharge coefficient. See the Appendix.

  7. Calculate new b -ration in accordance with equations in step c.

Case C Sub Critical flow

  1. First estimate for DPn:

  2. Calculate first estimate for b - ratio.

    1. For Venturi tubes:

    2. For other restriction devices:

  3. Calculate gas expansion factor (for liquids/water, Eps = 1)

    1. For Venturi tubes and nozzles:

    2. For orifice plates:

  4. Calculate discharge coefficient. See the Appendix.

  5. Calculate new b - ratio:

  6. Calculate new DP.

    1. For classical Venturi tube:

    2. For Nozzles:

    3. For orifice plates:

  7. Calculate new DPn:

  8. Calculate the relative change in DPn:

  9. In Case C, repeat steps c to h until the relative change in the DPn is less than 0.0001.

8. Calculate orifice diameter at flow temperature:

9. Calculate orifice diameter at ambient temperature.

  1. For Venturi tubes and nozzles:

  2. For orifice plates: