In real life, what should we do when the water pump fails? Let me explain to you some knowledge in this area. The so-called control valve instrument faults can be roughly divided into two categories, one is the fault of the instrument itself, and the other is the system fault, which is the fault of the instrument detection and control system during the production process.
1. Taike valve-water pump regulating valve instrument failure
The first type of failure, because the failure is relatively clear, the processing method is relatively simple. For this type of failure, the instrument maintenance personnel summarized a set of 10 methods for the judgment of the instrument failure.
1. Investigation method: Through the investigation and understanding of the failure phenomenon and its development process, analyze and judge the cause of the failure.
2. Intuitive inspection method: without any testing equipment, observe and find faults through human senses (eyes, ears, nose, hands).
3. Circuit breaking method: disconnect the suspected part from the whole machine or unit circuit, and see if the fault can disappear, so as to determine the fault location.
4. Short-circuit method: temporarily short-circuit a certain level of circuit or component that is suspected of being faulty, and observe whether there is any change in the fault state to determine the fault.
5. Replacement method: By replacing some components or circuit boards to determine the fault in a certain position.
6. Division method: In the process of finding faults, divide the circuit and electrical components into several parts to find out the cause of the fault.
7. Human body interference law: The human body is in a messy electromagnetic field (including the electromagnetic field generated by the AC grid), and it will induce a weak low-frequency electromotive force (near tens to hundreds of microvolts). When a human hand touches certain circuits of instruments and meters, the circuits will reflect. This principle can be used to easily determine certain faulty parts of the circuit.
8. Voltage method: The voltage method is to use a multimeter (or other voltmeter) to measure the suspected part with an appropriate range, and separately measure the AC voltage and the DC voltage.
9. Current method: The current method is divided into direct measurement and indirect measurement. Direct measurement is to connect an ammeter after the circuit is disconnected, and compare the measured current value with the value under the normal state of the meter to judge the fault. Indirect measurement does not open the circuit, measures the voltage drop on the resistance, and calculates the approximate current value based on the resistance value, which is mostly used for the measurement of the current of the transistor element.
10. Resistance method: The resistance inspection method is to check whether the input and output resistance of the whole circuit and part of the instrument is normal, whether the capacitor is broken or leaking, and whether the inductor and transformer are disconnected. Wire, short circuit, etc.
2. Taike valve-water pump regulating valve system failure
For the second type of instrument failure, that is, the instrument failure in the detection control system during the production process, it is more complicated. It is explained from three aspects: the importance, complexity and basic knowledge of fault handling.
1. The importance of troubleshooting
In the process of petroleum and chemical production, instrument failures often occur. Since the detection and control system is composed of several instruments (or components) through cables (or tubing), it is difficult to determine which link has failed. How to correctly judge and deal with instrument failures in a timely manner is directly related to the safety and stability of petroleum and chemical production, and the quality and consumption of chemical products. It also best reflects the actual working ability and business level of instrument workers and instrument technicians.
2, the complexity of fault handling
Due to the characteristics of pipelined, process-oriented, and fully enclosed petroleum and chemical production operations, especially the high level of automation in modern chemical companies, process operations are closely related to detection instruments. Process personnel display various process parameters, such as reaction temperature, through detection instruments. , Material flow, container pressure and liquid level, raw material composition, etc. to judge whether the process production is normal, whether the product quality is qualified, according to the instructions of the instrument to increase or reduce production, or even stop. The abnormal phenomenon of the indicator indication (the indication is high, low, unchanged, unstable, etc.), itself contains two factors:
(1) Process factors, the instrument faithfully reflects the abnormal conditions of the process;
(2) Instrument factor, due to a fault in a certain link of the instrument (measurement system), there is a misindication of the process parameters. These two factors are always mixed together, and it is difficult to judge immediately, which increases the complexity of instrument fault handling.
3. Basic knowledge of troubleshooting
Instrument technicians and instrument technicians must timely and accurately judge instrument failures. In addition to years of accumulated practical experience, they must be quite familiar with the working principle, structure, and performance characteristics of the instrument. In addition, it is necessary to be familiar with every link in the measurement control system, to understand the physical and chemical characteristics of the process medium, and the characteristics of the main chemical equipment. This can help the instrument technician to broaden his thinking and help analyze and judge the failure.
Post time: Sep-06-2021