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Simple understanding of the problem of pressure controller failure

Simple understanding of the problem of pressure controller failure
The pressure controller uses a metal 316L diaphragm type sensor that can be used for neutral oils, gaseous media, and water. The set value of the controller is adjustable, and the adjustment range -0.1~40MPa is optional. The pressure controller can be used to control the pressure of the gas, liquid or steam IIA, IIB, IIC CT1~CT6 group explosive gas mixture sites without corrosive effects on the pressure sensing elements. Pressure controllers have a lot of applications in production and life. There are a lot of movements in ships, vehicles, machinery, etc. However, many people may not be particularly familiar with controllers. So today we introduce some pressure control. Some simple knowledge of the device, including some explanation of the problem of failure, hopes to make everyone understand more.
The casing of the pressure controller is generally required to be grounded. The signal cable must not be mixed with the power cable. Strong electromagnetic interference should be avoided around the sensor and the transmitter. Sensors and transmitters should be cycled according to industry regulations during use.
Pressure controller common failure analysis and processing methods Capacitive pressure controller measurement part of the sensitive parts of the all-welded structure, the electronic circuit part of the wave soldering and connector installation, the overall structure of sturdy, durable, and very few failures. For the vast majority of users, if it is found that a sensitive component has failed, generally it cannot be repaired on its own. Contact the pressure controller manufacturer to replace its entire component.
The failure of the measuring part of the pressure transmitter in the measuring section of the pressure controller will cause the transmitter to have no output or the output is abnormal. Therefore, the transmitter must first be checked for its measurement-sensitive components. Remove the flange and inspect the isolation diaphragm of sensitive parts for deformation, breakage and oil leakage. Remove the compensation plate, do not take out sensitive parts, check the insulation resistance of the plug-in case, the insulation resistance should not be less than 100MΩ under the condition that the voltage does not exceed 100V. Turn on the circuit and gas circuit. When the pressure signal is the upper limit of the range, turn off the gas source, and the output voltage and reading value should be stable. If the output voltage drops, the transmitter is leaking and you can use soapy water to check for leaks.
The circuit of the pressure controller is checked and the power is turned on. After the input pressure signal is given, the status of the voltage signal at the output of the pressure controller is checked. If there is no output voltage, first check that the power supply voltage is normal; whether it meets the power supply requirements; whether there is any wiring error between the power supply and the pressure controller and the load device. If there is no voltage or reversed polarity on the pressure controller terminal, it will cause the transmitter to output no voltage signal. Exclude the above reasons, you should further check the amplifier board circuit components for damage problems; circuit board connectors have no contact with the phenomenon of bad, can be measured against the normal instrument measurement voltage and fault meter corresponding to the measured voltage compared to the method to determine the failure Point, if necessary, replace the faulty amplifier board. When checking flow-type pressure controllers, special attention should be paid to J-type amplifier boards to prevent static electricity.
After power on, if the pressure controller output is too high (greater than 10 VDC) or the output is too low (less than 2.0 VDC) after the input pressure signal is given, the output will not respond if the input pressure signal is changed and the zero point is adjusted and the range screw is turned on. . For such failures, in addition to checking whether there are any abnormalities in the sensitive components measured by the pressure controller, check whether the “oscillating control circuit part” on the amplifier board of the pressure controller is working normally or not. The normal peak voltage between the high-frequency pressure controller T1-12 should be 25~35VP-P; the frequency is about 32kHz. Secondly, check the operational status of each operational amplifier on the amplifier board; whether the components of each part are damaged or not. This type of fault requires the replacement of the amplifier board. Pressure controller in the line design and process assembly quality requirements are very strict, in the actual use of the line failure, after inspection confirmed that the good contact with the manufacturer to replace its fault circuit board to ensure the stability of the instrument long-term work And reliability.
Looking at the continuous improvement and provision of domestic pressure controller production technology, as a part of China's children, it is extremely proud and happy to have a strong industrial base for the motherland. Once again, I once again reminded the users of the vast majority of users: Please do not use products whose product quality has passed the expiration date because people’s life is only once. Please cherish life, and also make a sound and healthy development of the domestic economy. Some contributions. With the conditions of production and life users try to choose a big brand or smart, because the use of such a pressure controller is more safe and reliable.

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