Variable Area Flowmeter

Variable Area Flowmeter


Variable Area flow meters measure the volumetric flow of liquids and gases. This technology is based on the variable area principle, where flow raises a float in a tube, increasing the area for the passage of the fluid through the meter.


Variable area flowmeter is a simple, reliable, and inexpensive flow-measuring instrument. As a gas or liquid is introduced into a uniformly tapered flow tube a float rises, its weight supported by the fluid flowing underneath, until the entire volume of fluid can flow past the float. The position of the float corresponds to a point on the tube’s measurement scale and provides an indication of the fluid’s flow rate.

-Mechanical display and LCD
-Robust and universal
-The short-stroke design allows the measurement of a high flow rate using a relatively short metering tube
-Special application is for hazardous, dangerous, or aggressive fluid, for high temperature and high-pressure rates
-All stainless steel design provides a safe measurement of a variety of liquids, gases, and steam
-The measuring section can be equipped with a heating jacket
-Standard rotameter is mounted in a vertical pipeline with flow direction upwards


Diameter DN15-DN200
Measuring Range Water (20 C): 1-200000 L/h
Air(20 C, 0.1013 MPa): 0.03-6000m³/h
Range Ratio 10:1; special 20:1
Accuracy ±1.0% for liquid; ±1.5% for gas
Ambient Temperature Pointer type: -40℃~+85℃
Remote: +40℃~+85℃ (liquid crystal is not damaged)
-30℃~+80℃(liquid crystal is able to operate)
Medium Temperature SS304: -40℃~+100℃
PTFE: 0℃~100℃
High Temp.: 110℃~+450℃
Nominal Pressure DN15-DN50≤4.0MPA; DN80-DN20≤1.6MPa (common)
DN15-DN50≤32MPa; DN80-DN200≤16MPa (special)
Pressure Loss 7kPa- 70kPa
Viscosity DN15<5mPa.s: < 30mPa.s
Protect Level IP65
Output Pulse, 4-20mA, flow rate alarm
Alarm Output H& L Alarm
Switch value(1A@ 30V DC)
Relay output (1A@ 30V DC or 0.25A @ 250V AC or 0.5@ 125V AC)
Communication RS232, RS485, HART
Power Supply 4-20mA 24V DC (12V DC- 32V DC) 2 wires system
Alarm type: 4-20mA 24V DC (18V DC- 28V DC) 4 wires system
85- 265V AC 50Hz
Battery: 3.6V@ 7.5 AH (lithium)
Process Connection Flange (DIN, ANSI, JIS, etc.)
Sanitary Tri-clamp Type
Explosion-proof Exia II CT5Ex
Exd II BT6