Steam mass flow rate calculation by vortex flowmeter technology

Vortex flowmeter is more often used to saturated steam and superheated steam measuring, Comate vortex flowmeter range ration can be 1:35 mostly can meet the measure requirement on the site.

How to choose the dimension is right for your working condition?

Steam is a compressible fluid and volume varies with the temperature and pressure changes that make steam measurement by mass flow. Besides, mass flow is the first step to calculate the steam energy in custody transfer.

Vortex meter based on Karmen vortex street theory is widely used in the fluids measurement system, especially it’s a perfect skill act in steam, gas, and the clean, non-conductive liquid flow process measurement system.

Steam mass flow calculation formula:


M; steam mass flow, unit is kg/hr or T/hr;

ρ : density of steam, unit is kg/m3;

V: velocity of flow meter, unit is m/s;

D: pipe inner size, unit is mm;



Conditions: under given pipe size: DN50, working condition at 7barG, T= 170℃

Saturated steam mass flow calculation formula

Temperature and pressure are dependent variables, density can be calculated by measuring one single factor
according to the steam table:
density= 4.218 kg/m3;
F(volumetric flow)=14.1~494.4m3/hr;
V: 2~70m/s of VFM60MV;
M=59.6 ~ 2085.2kg/hr;

Superheated steam mass flow calculation formula

Temperature and pressure are independent variables. Needed to measure both factors to calculate the density to know mass flow then. For example, P=7barG, T=225℃

Calculation of velocity

Take above as case, mass flow around 1200kg/hr in DN50 pipe, the pressure at 7barG, T= 170℃;
density = 4.218kg/m3, to get F = 284.5m3/hr;
So velocity is 40.2m/s

Comate VFM60MV multi-variable vortex steam meter perfect skill match for steam process measurement

Fliud to measure Liquid, steam, gas
Nominal diameter Wafer/Flanged(ANSI/DIN/JIS):15mm~300mm(1/2″~12″)
Measurement range(m/s) Size DN15~20 DN25~32 DN40~300
Steam 6~70 m/s 4~70 m/s 2~70 m/s
Gas 6~60 m/s 4~60 m/s 2~60 m/s
Liquid 0.3~7m/s 0.3~7m/s 0.3~7m/s
Accuracy ±1% RD
Repeatability 0.3% RD
Output Pulse / 4~20mA / 4-20mA@ HART / RS-485
Process Temperature Range -40℃~150℃ ; -40℃~250℃ ; -40℃~350℃ ;

Bluetooth software in operating and after-sales support

This function enables users who have COMATE flow meter in site to reach and configure the parameters more easily rather than lose the case and check the manual on how to set it. Most important is COMATE R&D team will help you to do this job just get the device online and click online diagnosis, our team-member will collect the data and help you to check where the problems may come from!


•Bluetooth app on a cellphone to connect Comate flowmeters
•Home interface can review real-time readings on the meter screen
•Setting interface help to do function setting & parameter setting


•select output to pulse/4~20mA/frequency,
•select 4~20mA output parameters
•select unit of time/temperature/pressure/flow rate,etc
•input range of 4~20mA/pressure/temperature, etc
•Remote diagnosis function