Preventive measures before use
Maintaining the valve before use can greatly reduce the probability of its failure in operation, and it is a necessary means to ensure the long-term and efficient operation of the valve. Therefore, for power companies, it is necessary to formulate a corresponding maintenance system based on the basic types of valves, which mainly covers the basic installation, daily maintenance and fault maintenance of valves. First, when purchasing valves, it is necessary to combine them with relevant national regulations and relevant requirements; after purchasing valves, dedicated vehicles should be used to send them to the workshop. Of course, the valve must be well fixed to avoid damage during transportation. Secondly, when installing the valve equipment, it is necessary to maintain it in time. After all installations are completed, it is necessary to remove stains and oil stains on the valve to avoid any unnecessary impact on the normal operation and the overall service life. In addition, the technical department also needs to evaluate and predict the operating environment and service life of the valve components that have been installed, and timely replace and adjust the valves that have expired. Finally, power companies also need to formulate maintenance and repair plans and systems for different kinds of valves, and implement regular maintenance and repairs to effectively reduce the probability of failures of valves and greatly extend their service lives.
Maintenance before use
Regular maintenance of the valve before use can not only improve the efficiency of the normal operation of the valve, but also reduce the probability of the failure of the valve. First, in the transportation stage of the valve, under the premise of strictly complying with the relevant regulations, it is also necessary to properly store its related certificates, such as outer packaging, qualification certificates and installation instructions, and do a good job of moistureproof and anti-corrosion measures. After the valve is transported to the designated place, the relevant technical personnel also need to conduct a comprehensive inspection to see whether there is any damage to the outer packaging, the content of the certificate is clear and complete, and the valve component can be rotated smoothly. Second, when using a hoist to transfer the valve, it is necessary to ensure the safety of the hook, avoid scratches and damage to the valve by the sharp part of the hook, and avoid the probability of the failure of the valve due to the above phenomenon, or even cause the valve to be scrapped. Finally, in the welding operation of the valve, different greases should be selected according to the basic type of the valve, and the valve and pipeline should be properly protected; after the installation of the valve process is completed, an inspection should be performed. Check whether there is any looseness in the position of the connecting part, and the outlet of the sewage discharge pipe and pressure discharge pipe is in a locked state; in addition, in the welding process, tightness and pressure bearing will be greatly influenced due to damage to the valve. Therefore, after the welding process is completed, it is necessary to conduct a comprehensive inspection of the pressure capacity.
Installation and adjustment of valves
When testing the valve pressure, the method of injecting water into the pipeline is usually used, which mainly uses the water pressure to measure the final pressure bearing capacity of the valve. Before the water injection, it is necessary to use some pigs with the same diameter as the pipeline to clean up the debris inside the valve and the pipeline; in the process of water injection, it is necessary to ensure that the valve is completely in a fully open state, and its working state is supervised. Check whether there is any leakage. Once a problem occurs, the water injection must be stopped as soon as possible, and effective solutions must be taken. For the valve components that fail in the water injection process, a comprehensive evaluation of the quality should be carried out in the maintenance process. If they can't be used, they should be replaced in time.
When the water injection is completed, the staff needs to adjust the valve to a half-open state, and test the pressure bearing capacity. The pressure measurement time needs to be controlled within 4 to 24 hours. After completing the pressure measurement, it is necessary to completely clean up and remove the test water in the pipeline and valve, and adjust the valve to a fully open state. In the process of pressure measurement, professionals must conduct on-site supervision to prevent the increase of valve damage due to the wrong operation of the operator.
Maintenance after the valve being put into use
(1) Maintenance of transmission devices of valves
The transmission device is the most important part of the valve equipment. Of course, it is also the part with the highest failure rate. Therefore, the relevant personnel must do a good job in the repair and maintenance of this part. Some types of valves will be in a fully open or fully closed state during actual operation, and will only show a single change at important moments. Such an operating state will greatly reduce the degree of wear of the transmission. However, for some important valves, they will always be in a state of frequent opening and closing during the actual operation. In this state, the operating speed of the transmission will be increased and the degree of wear and tear will be increased. Therefore, in the process of installing the valve, it is necessary to add the grease in important parts to ensure the durability of the valve transmission.
(2) Precautions for adding grease to the valve
Valves that have been in operation for a long time need grease very much, but the amount of grease added must be strictly controlled. If there is too much grease, the valve will be too sensitive, which is very unfavorable for later regulation; On the contrary, if the grease is relatively not enough, it will increase the operating resistance of the valve and increase the wear degree of the internal parts of the valve. It can be seen that high-quality and appropriate amount of grease is very important for the normal operation of the valve.
(3) Maintenance of packings of valves
The packing in the valve is to ensure the air tightness of the valve. If the packing in the valve fails or the weight is insufficient, the overall tightness of the valve will be seriously affected, and even the valve will lose its function. What affects the packing in the valve is not only the transported material in the pipeline, but also the high temperature generated by the long-term operation. These factors will accelerate the aging speed of the packing in the valve. Therefore, in the daily repair and maintenance of the valve, it is necessary to do a good job for the packing to ensure that there is no leakage, and reinforce and tighten the screws around it. Some types of valves need to be lubricated during the packing operation. The purpose of grease is to make the valve have good performance in the future. Of course, in the process of maintenance, it is necessary to add some lubricating grease inside the packing to make it lubricate and protect.
