Advantages, disadvantages and classification of Venturi flowmeter
If it can be manufactured precisely according to ASME standards, the measurement accuracy can also reach 0.5%. However, due to manufacturing technology issues, it is difficult to guarantee the accuracy of domestically produced Venturi flow meters. Kaifeng Instrument Factory, which has strong technical strength and old qualifications in China, can only guarantee a measurement accuracy of 4%. For ultra supercritical power generation conditions, the use of the pressure equalization ring at the throat is a very dangerous link. Without using the pressure equalization ring, it does not meet the standards, and the measurement accuracy cannot be guaranteed. This is a contradiction in the manufacturing of high-pressure classical Venturi flow meters.
The disadvantage of the Venturi flowmeter is that the throat is made of the same material as the inlet and outlet, and the fluid has severe erosion and wear on the throat, which cannot guarantee long-term measurement accuracy. The structural length must be manufactured according to regulations, otherwise the required accuracy cannot be achieved. Due to strict structural regulations for the classic Venturi, its flow measurement range is limited to a maximum and minimum flow ratio of 3 to 5. This makes it difficult for the Venturi flowmeter to meet the requirements of flow measurement with large changes in flow rate.