The high corrosiveness of the medium poses a serious threat to flow meters, and only individual types of flow meters such as clamp-on ultrasonic flow meters and anti-highly corrosive flow meters are less affected by corrosion.
a. The key components of the flow meter that come into direct contact with the highly corrosive medium will be corroded, causing damage and loss of function. For example, the diaphragm of the differential pressure transmitter is damaged by the highly corrosive medium, resulting in silicone oil leakage and complete failure. In electromagnetic flow meters, electrodes cause medium leakage due to high corrosion, leading to the burning of excitation coils.
b. The critical components of the flow meter change in geometric dimensions over a long period of time due to corrosion from highly corrosive media, which leads to reduced accuracy of the instrument. For example, in rotor flow meters, the rotor is corroded by the fluid, reducing its size and causing the flow meter reading to be lower than actual. In vortex flow meters, the vortex shedding body is corroded by the fluid, reducing its width and making the upstream surface rougher, thereby changing the flow coefficient. Even the clamp-on ultrasonic flow meter, which is less affected by highly corrosive media, often experiences weakened transmission and reception signals due to the pitted inner walls of metal pipes caused by medium corrosion, and in severe cases, loses sensitivity.
c. Shorten the life of the flow meter. For example, parts such as the conical tube in metal-tube rotor flow meters can become perforated at their welded joints after several years of use.
d. Leakage of highly corrosive media, if not promptly discovered and handled, can easily lead to safety and personal accidents.