Flow Meter Differential Pressure Type

Differential pressure flowmeter is an instrument that calculates the flow rate based on the differential pressure generated by the interaction between the flow detection device installed in the pipeline and the fluid, known fluid conditions, and the geometric dimensions of the detection device and the pipeline.
The differential pressure flowmeter consists of a primary device (detection component) and a secondary device (differential pressure converter and flow display instrument). Differential pressure flow meters are usually classified in the form of detection components, such as orifice flow meters, Venturi flow meters, uniform velocity tube flow meters, Pitot tube principle Pitot bar flow meters, etc.
The secondary device includes various mechanical, electronic, and electromechanical integrated differential pressure gauges, differential pressure transmitters, and flow display instruments. It has developed into a large class of instruments with a high degree of standardization (serialization, generalization, and standardization) and a wide variety of specifications. It can measure both flow parameters and other parameters (such as pressure, level, density, etc.).
The detection components of differential pressure flow meters can be divided into several categories based on their working principles: throttling device, hydraulic resistance type, centrifugal type, dynamic pressure head type, dynamic pressure head gain type, and jet type.
The test pieces can be divided into two categories based on their degree of standardization: standard and non-standard.
The so-called standard testing parts can determine their flow values and estimate measurement errors as long as they are designed, manufactured, installed, and used according to standard documents, without the need for actual flow calibration.
Non standard test pieces are those with poor maturity and have not yet been included in international standards. Differential pressure flowmeter is the most widely used type of flowmeter, with its usage ranking first among various flow instruments. Due to the emergence of various new flow meters, their usage percentage has gradually decreased, but they are still the most important type of flow meter at present.
The formula for fluid volume flow rate of differential pressure flowmeter is:
V=aA √ 2/j (p-q)
V - Volume
J - Liquid density
A - Flow coefficient, related to the pressure measurement method and flow velocity announcement of the channel size
A - Opening area of orifice plate
P-q - Pressure difference