TABLE OF CONTENTS Turbine flowmeters are designed to accurately measure the flow of liquids and gases in pipes. They are a volumetric flow-measuring device. The range of flow is from 0.001 gpm to over 25,000 gpm for liquid service and 0.001 acfm to over 25,000 acfm for gas service. The flowmeters are typically manufactured from stainless steel, but also available in a variety of materials, including plastic. Turbine meters are applicable to all clean fluids over a pressure range from sub-atmospheric to over 60,000 psi and temperatures from cryogenic to about 800 degrees C (1500 degrees F).
The turbine flowmeter is perhaps the most accurate type of meter available. A turbine meter has only one moving part a rotor. The output signal from the flowmeter and sensor is an electronic pulse, but other output signals such as analog, visual, or digital are available.
Turbine meters are used on clean fluids or gases when a very accurate measurement is required. The device has a threshold velocity but becomes a very accurate flow measurement once the threshold velocity is exceeded. Since blade configuration is important, any form of trash must be kept from entering the bladed area. For this reason, filters are sometimes placed upstream of the meter to prevent damage to the blading. Bearing and blade material must be compatible with the process material, and there must be sufficient upstream and downstream straight pipe for accurate measurement. Flow straightening tubes are sometimes used when there is not sufficient straight upstream piping.
