ROTAMETER
What are Rotameters ?
The rotameter is an industrial flowmeter used to measure the flowrate of liquids
and gases. The rotameter consists of a tube and float. The float response to
flowrate changes is linear, and a 10-to-1 flow range or turndown is standard. In the
case of Flowtel Engineering, far greater flexibility is possible through the use of
correlation equations. The rotameter is popular because it has a linear scale, a
relatively long measurement range, and low pressure drop. It is simple to install
and maintain.
Acrylic tubes are also used in some rotameter designs due
to their lower cost and high impact strength. They are
typically constructed of acrylic, with either metal or plastic
end fittings. With plastic end fittings, care must be taken in
installation, 
For higher pressures and temperatures beyond the practical range of glass tubes, metal
tubes are used. These are
usually manufactured in stainless steel. The position of the
float is determined by magnetic or mechanical followers that can be read from the
outside of the metal metering tube. 
The glass tube rotameter is precision formed of borosilicate glass, and the float is precisely machined from metal, or plastic. The
metal float is usually made of stainless steel to provide corrosion resistance. The float has a sharp metering edge/maximum
diameter where the reading is obser ved by means of a scale mounted 
When fluid or gas flows through a taper tube containing a float, a pressure difference of
P1 and P2 is created between upper and lower side of the float. The float moves upwards by a force
obtained by multiplying the pressure differential by the maximum cross sectional area of the float. 
A removable mechanism type Woltman Water meter /multijet
dry With magnetic drive and vacuum sealed register. 
The bore and bevel is the standard method of limiting the plate edge thickness. The bevel is
machined at a 45° angle to the desired edge thickness. Unless otherwise specified, plates will be
bevelled to 1/50 of the line I.D. or 1/8 of the orifice bore, minimum governing. 
Flowtel series FLTF100 2 wire /FLTF200 4 wire turbine flow transmitter
specially used for various industrial applications. The flowing media engages
a vaned rotor causing it to rotate at an angular velocity proportional to flow
rate.