Pipeng Toolbox : Steam Nozzle Calculators Login
Short Cuts
GO
Main ±
Beams ±
References ±
Fluid Flow ±
Fluid Properties ±
Maths ±
Materials ±
Pipelines ±
Soils ±
Subsea ±
Data ±
Units ±
Help ±
Demo

IAPWS R7-97 Steam Nozzle

Calculate IAPWS R7-97 isentropic steam nozzle flow properties from stagnation temperature and pressure.

For critical flow the mass flux is a maximum (theoretical critical Mach number equals 1). The flowing velocity is calculated from the stagnation enthalpy (ho = h + 1/2 V^2). If the ambient pressure is greater than the critical nozzle pressure the flow is sub critical. Flow properties are valid for the vapour phase only. Check the nozzle density and Mach number to ensure the calculations are valid. The anomaly zone is set to region 2 (region 3 does not converge properly). Use the Result Plot option to plot isentropic nozzle properties versus stagnation temperature and pressure, and mass flow rate versus either nozzle diameter or nozzle area (the plot calculation is slow - a modern browser is recommended).

Note : There is an anomaly in the steam calculation for region 3 between the saturated vapour line, the region 2/3 boundary, and the critical pressure. Refer to the region 3 anomaly help page for more details (click the utility button on the data bar). IAPWS R7-97 is intended for industrial use, and is a simplified version of IAPWS R6-95 for scientific use. IAPWS R7-97 was developed as an improvement of the IFC-67 model.

Reference : IAPWS R7-97 Industrial Formulation for thermodynamic Properties of Water and Steam

Change Module :

[FREE] tools are free in basic mode with no login (no plots, tables, goal seek etc). Login or Open a free account to use the tools in plus mode (with plots, tables, goal seek etc).
[PLUS] tools are free in basic CHECK mode with Login or Open a free account (CHECK values no plots, tables, goal seek etc). Buy a Subscription to use the tools in plus mode (with plots, tables, goal seek etc).
Try plus mode using the Plus Mode Demo tools with no login.   Help Using The Pipeng Toolbox (opens in the popup workbook)

Links : ±
CALCULATOR : IAPWS R7-97 Steam Table [FREE]   ±

Calculate steam table from temperature and pressure (IAPWS R7-97 Steam Table).

Steam table values can be calculated for water and steam, saturated water, saturated steam, saturated water and steam, metastable water, and metastable steam. The calculations for water and steam are valid between 273.15 K and 1073.15 K (0 to 100 MPa), and between 1073.15 K and 2273.15 K (0 to 50 MPa).

The saturated water and steam calculations are valid between 273.15 K and 647.096 K.

The metastable calculation is valid between 273.15 K and 647.096 K, and for pressure from the saturated vapour line to the 5% equilibium moisture line (user defined). Use the Result Plot option to plot the steam properties versus temperature and pressure.

Tool Input

  • anomtype : Region 2/3 Anomaly Type
  • proptype : Steam Phase
    • Pu : User Defined Pressure
    • Tu : User Defined Temperature
    • Xu : User Defined Saturated Steam Quality

Tool Output

  • ρ : Density
  • Cp : Specific Heat Constant Pressure
  • Cp-Cv : Delta Specific Heat (Cp - Cv)
  • Cp/Cv : Specific Heat Ratio
  • Cv : Specific Heat Constant Volume
  • P : Pressure
  • T : Temperature
  • Vc : Speed Of Sound
  • Z : Compressibility Factor
  • cvg : Convergence Check
  • h : Enthalpy
  • s : Entropy
  • u : Internal Energy
  • vg : Mole Specific Volume
  • vm : Specific Volume
  • wv : Specific Weight

CALCULATOR : IAPWS R7-97 Steam Nozzle [PLUS]   ±

Calculate steam isentropic mass flow rate through a nozzle or pressure relief valve from stagnation temperature and pressure, and nozzle pressure (IAPWS R7-97 steam table).

If the ambient pressure is less than or equal to the critical pressure, the nozzle flow is critical. If the ambient pressure is greater than the critical pressure, the nozzle flow is sub critical. theoretical critical Mach number for isentropic flow equals one. The mass flux rate is a maximum at the critical point. Flow properties can be calculated at either stagnation conditions or at the nozzle conditions. The anomaly zone is set to region 2 (region 3 does not converge properly). The flowing velocity is calculated from the stagnation enthalpy.

Note : Critical flow is calculated from the steam table. The calculation is not valid for the liquid phase. For stagnation temperatures less than the critical point, the stagnation pressure is set to be less than or equal to the vapour pressure. Check the nozzle density and Mach number to ensure the calculations are valid. Use the Result Plot option to plot isentropic nozzle properties versus stagnation temperature and pressure, and mass flow rate versus either nozzle diameter or nozzle area.

Tool Input

  • antype : STD Type
    • Dnu : User Defined Nozzle Diameter
    • Anu : User Defined Nozzle Area
  • cdtype : Factor Type
    • Cdu : User Defined Discharge Coefficient
  • proptype : Stagnation Steam Phase
    • Pou : User Defined Stagnation Pressure
    • Tou : User Defined Stagnation Temperature
    • Xou : User Defined Stagnation Steam Quality
  • modetype : Fluid Property Type
  • Pa : Ambient Pressure

Tool Output

  • ρ : Density
  • An : Nozzle Area
  • Cp : Specific Heat Constant Pressure
  • Cp-Cv : Delta Specific Heat (Cp - Cv)
  • Cp/Cv : Specific Heat Ratio
  • Cv : Specific Heat Constant Volume
  • Gn : Nozzle Mass Flux
  • M : Nozzle Mach Number
  • Pn : Nozzle Pressure
  • Po : Stagnation Pressure
  • Tn : Nozzle Temperature
  • To : Stagnation Temperature
  • Vc : Speed Of Sound
  • Vn : Nozzle Velocity
  • Xn : Nozzle Steam Quality (Saturated Liquid And Vapour Only)
  • Z : Compressibility Factor
  • cd : Discharge Coefficient
  • cvg : Convergence Check
  • h : Enthalpy
  • ho : Stagnation Enthalpy
  • mn : Mass Flow Rate
  • s : Entropy
  • so : Stagnation Entropy
  • u : Internal Energy
  • vg : Mole Specific Volume
  • vm : Specific Volume
  • wv : Specific Weight

CALCULATOR : IAPWS R7-97 Steam Nozzle Orifice Diameter And Cross Section Area [FREE]   ±

Calculate IAPWS R7-97 steam effective nozzle orifice diameter and cross section area from API letter designation (API 526 type D to T).

Pressure relief valve calculations are based on frictionless flow, however there are significant friction losses incurred in a pressure relief valve. API effective orifice sizing is used to compensate for the pressure losses in relief valves (the actual nozzle area is greater than the effective nozzle area). The combination of valve and nozzle must be tested with the operating fluid, and certified as having a flow rate greater than or equal to the calculated flow rate for the effective size. The API 526 flow rate is calculated for isentropic flow. For non API certified valves, use the nozzle diameter as an actual diameter with an appropriate discharge coefficient.

Use the Result Table option to display a table of effective area and effective diameter versus nozzle API letter designation (D to T).

Tool Input

  • antype : Nozzle Orifice Type
    • Dnu : User Defined Nozzle Diameter
    • Anu : User Defined Nozzle Area

Tool Output

  • An : Nozzle Effective Area
  • Dn : Nozzle Effective Diameter