Pipe flow calculators
Calculator Description
Nozzles and Venturi nozzles are devices that are inserted in circular crosssection conduit to create pressure difference of static pressure. Based on that pressure difference, flow rate of flowing fluid can be calculated.

Calculate:
 Volumetric or weight Flow rate
 Flow velocity in the nozzle inlet and throat
 Discharge coefficient for compressible flow
 Gas expansion coefficient for compressible flow
 Reynolds numbers

Input:
 Pressure difference at inlet and throat of nozzle
 Nozzle inlet and throat diameter
 Fluid density
 Fluid viscosity
Calculator Features
 Conversion between volumetric and weight flow rate
 Calculation of Reynolds number included
 Applicable for noncompressible liquids and compressible perfect gases
 Pressure ratio p_{2}/p_{1} must be equal or greater than 0.75
 For singlephase fluid, subsonic, nonpulsating flow
 ISO 5167 based calculation
 Long radius, regular and Venturi nozzle types
Three types of nozzles are covered in calculator: ISA 1932 nozzle, long radius nozzle and Venturi nozzle. All three types differ from each other based on its shape. All nozzles have radius shaped convergent inlet with cylindrical throat and Venturi nozzle also has divergent part as outlet.
Calculation of gas flow with higher pressure drop and flow close or equal to choked flow conditions gas discharge calculator should be used.
Limits of use for nozzles are:
 50 mm < D < 500 mm
 0.3 < β < 0.8
 7x10^{4} < Re_{D} < 10^{7} for 0.3 < β < 0.44
 2x10^{4} < Re_{D} < 10^{7} for 0.44 < β < 0.80
Limits of use for long radius nozzles are:
 50 mm < D < 630 mm
 0.2 < β < 0.8
 10^{4} < Re_{D} < 10^{7}
Limits of use for Venturi nozzles are:
 65 mm < D < 500 mm
 0.316 < β < 0.775
 1.5x10^{5} < Re_{D} < 2x10^{6}
Values for coefficient of discharge or flow coefficient (C or C_{d}) can be calculated based on applicable standards like ISO 5167 or similar ASME standards.
Please tell me what do you think about this calculator
Q: Calculate flow rate of air flowing through nozzle with pipe diameter of 200 mm and nozzle throat diameter of 100 mm, at 288 K. Measured pressures in front and in the throat of nozzle are 104000 Pa and 101325 Pa.
A: Calculation setup:
Flowing fluid: gas
Input one from following two:
p_{2}  absolute pressure after the orifice
T  temperature
ni  kinematic viscosity
Enter values:
D_{1} = 200 mm
D_{2} = 100 mm
p_{1} = 104000 Pa (absolute)
p_{2} = 101325 Pa (absolute)
ni = 13.4 mm^{2}/s
T = 288 K
R = 287 J/kgK
kappa = 1.4
select nozzle type  nozzle
Q: Calculate flow rate of water flowing through nozzle with pipe diameter of 200 mm and throat diameter of 150 mm. Measured pressure in front of nozzle is 1015 mbar and pressure drop in nozzle is 5 mbar.
A: Calculation setup:
Calculate for: liquid
Input one from following two:
p_{1}  p_{2}  pressure drop
T  temperature
ni  kinematic viscosity
Enter values:
D_{1} = 200 mm
D_{2} = 150 mm
p_{1} = 1015 mbar (absolute)
p_{1}  p_{2} = 5 mbar (absolute)
ni = 1.006 mm^{2}/s
rho = 1000 kg/m^{3}
select nozzle type  nozzle
Q: Calculate flow rate of water flowing through nozzle to open atmosphere from 25 mm pipe pressurized with 1.5 bar absolute pressure. Nozzle diameter is 3 mm.
A: Calculation setup:
Calculate for: liquid
Input one from following two:
p_{2}  absolute pressure after the orifice
ni  kinematic viscosity
Enter values:
D_{1} = 25 mm
D_{2} = 3 mm
p_{1} = 1.5 bar (absolute)
p_{2} = 101325 Pa (absolute)
ni = 1.006 mm^{2}/s
rho = 1000 kg/m^{3}
select nozzle type  nozzle
Equation used for flow through nozzle calculation:
Read more about used theory on flow in valves and fittings page.
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