The gas flow meter is considered to be a specialised device used for measuring fuel gas volume like liquefied petroleum gas and natural gas. It is used mainly at industrial, commercial and residential buildings consuming fuel gas that the gas utility supplies. Unlike liquids, gases are not easily measurable. The reason is pressure and temperature affects significantly the measured volumes. Gas meters are known measure defined volume, irrespective of gas quality or pressurizing quantity flowing via the meter. Heating value compensation, pressure and temperature should measure actual gas moving value and amount through the meter.
Flow Meter types
- Rotary Meters: These are highly machined precision devices designed with the ability to manage very high pressures and volumes. It features ‘8’ shaped, two lobes and rotors that spin in accurate alignment. They move gas in specific quantity with each turn through the meter. The primary flow element here is the crank shafts rotational movement. For flow computer, it can produce electrical pulses.
- Bellows/Diaphragm meters: It is a common Paperless Recorder type used in small commercial and residential installations. There are present a couple or more chambers that its movable diaphragms form. The internal valves direct the gas flow while chambers fill as well as expel gas alternately, thereby producing flow continuously via the meter. With the contraction and expansion of the diaphragms, the levers connected with the cranks transform the diaphragms’ linear motion to the crank shaft’s rotary motion.
- Office meters: It comprises of a straight pipe length within the meter, referred to as orifice plate. Its function to develop a pressure drop, thus affecting flow. This differential meter infers gas flow rate by measuring pressure difference across carefully designed as well as installed flow disturbance. It is essential to measure gas static pressure, temperature, viscosity and density. But this device is not designed to manage large flow rates. But they do find good use in industrial applications as they do not have moving parts or easy to field-service. You can refer to reputed portals like https://www.silverinstruments.com for more information.
- Turbine meter: These are Low flow gas flow meter that infers gas volume. It is done by determining gas flow speed through the meter. Since gas volume is flow inferred, flow conditions should be good. Gas speed is measured by a small internal turbine. The gas is mechanically transmitted to electronic or mechanical counter. Such meters are not known to impede gas flow, however, are limited by lower flow rate measures.
- Coriolis Meters: This is an ultra low flow meter having one or several pipes with axially or longitudinally displaced sections. Their function is to vibrate at a given resonant frequency. This device is used with gases and liquids. As fluid present in the displaced section is found to be at rest, the displaced section’s downstream and upstream is likely to vibrate in phases with one another. Vibrancy frequency is determined by the pipe’s overall density. Thus, gas flowing density can be measured by the meter in real time.
Therefore, getting to know about low flow mass flow meter can help with the selection process.
