Title and Link to Calc:

Compressible Fluid Flow : Flow in Globe Valves : CFF-CRFOF-0008

Description:

Calculates flow parameters in a globe valves similar to Examples 4-1, 4-2 and 4-3 in Flow of Fluids Through Valves, Fittings, and Pipe, 1988 (reprinted 12/01), Crane Co. , K Values are calculated at complete turbulence per page page A-26 through A-29 of the reference. The flowrate of a specified fluid and 60 F air is calculated at the input pressure conditions. The flow coefficent and equivalent lengths are also calculated.

Alternative Descriptors:

Air Flow in Globe Valves, K of Globe Valves, Cv of Globe Valves, Pressure drop in Globe valves, Flow coefficient of Globe valves, Head Loss in Globe valves, Resistance coefficient of Globe valves, Flow of Compressible Fluids through Globe Valves, Equivalent Length of Globe valves.

Calc Number:

CFF-CRFOF-0008

Calc Status:

Beta

Reference:

(1) Flow of Fluids Through Valves, Fittings, and Pipe, 1988 (reprinted 12/01), Crane Co.

Reference Example(s) Modeled/Generalized:

Examples 4-1, 4-2, and 4-3 of the above reference

Calc Origination Date:

02/27/2006

Calc Originator:

RBC

Calc Revision History:

Calc Guidelines:

See the above reference

Access:

Activating this calc requires entry of the correct access code. Contact eng-calc@eng-calcs.com

Variables:

Variable Description - Description of the variable
Variable Label Description - The description of the variable as it appears in the calc.
Variable Calc Name - The calc internal variable name
Variable Units - The units for the variable
Variable Calc Upper Limit - The highest allowed value in the calc.
Variable Calc Lower Limit - The lowest allowed value in the calc.
Variable Type - Either "Output" or "Input"
Variable Format - Real Number, Text, or Integer
Variable Notes - Other comments about the variable

Variable Description: Resistance Coefficient, K, based on the upstream pipe inside (large) diameter
Variable Label Description: Resistance Coefficient [K]
Variable Calc Name: KEQ
Variable Units:
Variable Calc Upper Limit: 100000
Variable Calc Lower Limit: 0
Variable Type: Output
Variable Format: REAL
Variable Notes:

Variable Description: Equivalent Length of Globe Valve based on the upstream pipe inside (large) diameter
Variable Label Description: Equivalent Length
Variable Calc Name: EQL
Variable Units: FT
Variable Calc Upper Limit: 100000
Variable Calc Lower Limit: 0
Variable Type: Output
Variable Format: REAL
Variable Notes:

Variable Description: Darcy Friction Factor based on the upstream pipe inside (large) diameter
Variable Label Description: Darcy Pipe Friction Factor
Variable Calc Name: FF
Variable Units:
Variable Calc Upper Limit: 100000
Variable Calc Lower Limit: 0
Variable Type: Output
Variable Format: REAL
Variable Notes:

Variable Description: Flow Coefficient , Cv
Variable Label Description: Flow Coefficient [Cv]
Variable Calc Name: CV
Variable Units:
Variable Calc Upper Limit: 100000
Variable Calc Lower Limit: 0
Variable Type: Output
Variable Format: REAL
Variable Notes:

Variable Description: Mass Flow Rate of Specified Fluid
Variable Label Description: Specified Fluid Mass Flow Rate
Variable Calc Name: MFRS
Variable Units: LBM/SEC
Variable Calc Upper Limit: 100000000
Variable Calc Lower Limit: 0
Variable Type: Output
Variable Format: REAL
Variable Notes: Flow rate calculated using equation 3-20 of reference. Expansion factor assumed to equal one.

Variable Description: Mass Flow Rate of 60 F Air through Valve
Variable Label Description: Air Mass Flow Rate [60 F]
Variable Calc Name: MFRA
Variable Units: LBM/SEC
Variable Calc Upper Limit: 100000000
Variable Calc Lower Limit: 0
Variable Type: Output
Variable Format: REAL
Variable Notes: Ideal Gas Law Used to Estimate Air Density at Input Pressure & 60 F. Flow rate calculated using equation 3-20 of reference. Expansion factor assumed to equal one.

Variable Description: Comments
Variable Label Description: Comments
Variable Calc Name: COM
Variable Units:
Variable Calc Upper Limit:
Variable Calc Lower Limit:
Variable Type: Output
Variable Format: TEXT
Variable Notes: Displays "Input(s) out of range." if an entered input variable(s) are out of range. Displays "Output(s) out of range." if an output variable exceeds its range. The "out of range" variable(s) are displayed in yellow. The limited range values are used in the calculation, not the "out of range" value(s).

Variable Description: Upstream (Large) Pipe (inside) Diameter at Entrance of Fitting
Variable Label Description: Pipe Upstream Inside Diameter
Variable Calc Name: PID
Variable Units: IN
Variable Calc Upper Limit: 300
Variable Calc Lower Limit: 0.01
Variable Type: Input
Variable Format: REAL
Variable Notes:

Variable Description: Beta of Valve Throat Diameter to Inside diameter of Inlet Pipe
Variable Label Description: Valve Beta
Variable Calc Name: BVAL
Variable Units:
Variable Calc Upper Limit: 1
Variable Calc Lower Limit: 0.05
Variable Type: Input
Variable Format: REAL
Variable Notes: See diagram on page A-27 of reference

Variable Description: Fitting Upstream Pressure
Variable Label Description: Upstream Pressure
Variable Calc Name: UPA
Variable Units: PSIA
Variable Calc Upper Limit: 10000
Variable Calc Lower Limit: 0.001
Variable Type: Input
Variable Format: REAL
Variable Notes: This value is used to calculate the flow rate of the fluids through the valve.

Variable Description: Pressure Ratio = (UPA-DPRE)/(UPA) , Difference of Upstream Pressure & Downstream Pressure divided by the Upstream Pressure
Variable Label Description: Pressure Ratio
Variable Calc Name: DPA
Variable Units:
Variable Calc Upper Limit: 0.1
Variable Calc Lower Limit: 0.001
Variable Type: Input
Variable Format: REAL
Variable Notes: Cannot be greater than 0.1

Variable Description: Specified Fluid Specific Volume at Upstream Condition
Variable Label Description: Fluid Specific Volume
Variable Calc Name: FSG
Variable Units: CUFT/LBM
Variable Calc Upper Limit: 10000
Variable Calc Lower Limit: 0.001
Variable Type: Input
Variable Format: REAL
Variable Notes:

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