Differential Pressure Flowmeters Differential pressure flowmeters are differential pressure flowmeters that are installed on differential pressures generated by flow detection elements in industrial pipelines to measure the known fluid conditions and the geometry of the test pieces and piping. Differential pressure flowmeter consists of a test piece and a secondary instrument (differential pressure transducer or transmitter and flow display instrument). The differential pressure flowmeters are classified in the form of test pieces, including orifice plate flowmeters, venturi flowmeters, and constant velocity tube flowmeters. The secondary instrument is a variety of mechanical, electronic, electromechanical differential pressure flow meter, differential pressure transmitter and flow display instrument. Differential pressure flow meter is the most widely used medium flow meter in the large family of flow meters. At present, it has been serialized, generalized and standardized at home and abroad. Differential pressure flow meter can measure flow parameters separately, and can also measure other parameters ( Pressure, level, density, etc. Differential pressure flow meter detection parts according to its principle can be divided into: throttling device, hydraulic resistance, dynamic pressure head type, dynamic pressure head gain and jet type, and centrifugal type several major categories. There are two types of test items, standardized or non-standard. Standard type detection elements are designed, manufactured, installed, and used in standard documents. Flow measurements and estimated measurement errors can be determined without real-world calibration. Non-standard type detection elements are generally not included in the international standards for detection components. Differential pressure flowmeters are also the most widely used type of flow meter and occupy the first place in the use of various flow meters.
Volumetric flowmeters, also known as fixed displacement flowmeters, referred to as PD flowmeters, are among the most accurate in flow meters. It uses a mechanical measuring element to continuously divide the fluid into a single known volume fraction, measuring the total volume of fluid according to the number of times that the measurement chamber fills and discharges the volume fraction of fluid sequentially and repeatedly. Volumetric flowmeters are classified according to their measuring components: elliptical gear flowmeters, rotary piston flowmeters, reciprocating piston flowmeters, disk flowmeters, wet gas meters, diaphragm gas meters, and liquid-sealed tumbler flowmeters.