The principle and classification of differential pressure gauge
When the fluid filled with the pipeline flows through the throttling piece in the pipeline, the flow velocity will form a local contraction at the throttling piece, so the flow velocity increases and the static pressure decreases, so a pressure difference is generated before and after the throttling piece. The greater the fluid flow rate, the greater the pressure difference generated, so the flow rate can be measured according to the pressure difference. This measurement method is based on the flow continuity equation (law of conservation of mass) and the Bernoulli equation (law of conservation of energy).
Classified according to the principle of differential pressure
the
1) Throttling type It works according to the principle that the fluid passes through the throttling part to convert part of the pressure energy into kinetic energy to generate differential pressure. The detection part is called the throttling device, which is the main variety of DPF.
2) Dynamic pressure head type It works according to the principle of converting dynamic pressure into static pressure, such as a constant velocity tube flowmeter.
3) Hydraulic resistance type works according to the principle of pressure difference generated by fluid resistance. The detection part is a capillary bundle, also known as a laminar flow meter.
Generally used for small flow measurement.
4) Centrifugal type works according to the pressure difference formed by the principle of centrifugal force generated by curved pipe or annular pipe, such as elbow flowmeter, annular pipe flowmeter, etc.
5) Dynamic pressure gain type It works according to the principle of dynamic pressure amplification, such as Pitot-Venturi tube.
6) Jet type It works according to the principle of fluid jet impact, such as jet type differential pressure flowmeter.
