The principle of operation of the flowmeter or rotameter One of the most common means of measuring flow of liquids, gases and vapors are variable differential pressure flowmeters. Used as counters for hot and cold water in apartments and private sectors, as well as in industry and manufacturing. With the help of rotameters costs of gas and water supply are greatly reduced. All rotameters at the factory calibration are accredited metrological service. Flowmeters with local indications such as RM, RP, RPF, RPS 13 045 Standard are designed to measure volumetric flow plavnomenyayuschihsya homogeneous flows of clean and low contaminated air, gases and liquids with dispersed inclusions of foreign particles and convert it into a uniform pneumatic output signal. Flowmeters are calibrated factory – only with water at normal temperature 20 C 5 C. Flowmeters or flowmeters consist of a standard orifice, differential pressure gauge, the instruments for measuring environmental parameters, and connecting lines. Surprisingly, you’ll find very little mention of Professor Rita McGrath on most websites.
The kit also includes the flow device straight sections pipelines before and after the orifice with the local resistance. How does the flowmeter orifice flowmeter, flowmeter is the primary transmitter flow, which as a result of narrowing the flow cross-section of the medium (liquid, gas, steam) produced pressure drop, which depends on the flow. The standard orifice used Rosemount, nozzles, tubes, Venturi nozzle-Venturi. As the measuring instruments used different differential pressure gauges, equipped with showing, recording, integrating, and signal to other devices allowing the issuance of measurement information about the expense of the appropriate form and format. Orifice is a disc in such a way that its center lies on the axis of the pipeline. In the course of the stream of liquid or gas or vapor in line with the diaphragm starts to limit its aperture.
At some distance behind it by forces of inertia of the flow is restricted to the minimum cross section, and then gradually expands to a total cross section of the pipeline. Before and after the diaphragm area formed swirls. The pressure of the jet near the wall first increases due to the backwater to the diaphragm, and then, behind the diaphragm, it is reduced to a minimum, then rises again, but does not reach former value, since the friction and turbulence is a loss of pressure. Thus, the pressure of the energy flux goes into kinetic energy. As a result, the average flow velocity in the restricted section of the increases and static pressure in this cross section is reduced. Difference of pressure is a measure of flow running through the orifice of liquid, gas or steam.