Maintenance and upkeep of valves

Valve storage and maintenance

1. The purpose of storage and maintenance is to prevent valve damage or reduce quality during storage. In fact, improper storage is one of the important reasons for valve damage.
2. Valves should be kept in an orderly manner. Small valves should be placed on shelves, while large valves can be neatly arranged on the warehouse floor. They should not be piled up or stacked randomly, and the flange connection surface should not come into contact with the ground. This is not only for the sake of aesthetics, but also to protect the valve from damage.
3. Due to improper storage and handling, the handwheel is broken, the valve stem is tilted, and the fixing nut between the handwheel and the valve stem is loose and lost. These unnecessary losses should be avoided.
4. For valves that are not in use for a short period of time, asbestos packing should be removed to avoid electrochemical corrosion and damage to the valve stem.
5. For valves that have just entered the warehouse, they should be inspected. If rainwater or dirt enters during transportation, they should be wiped clean before being stored.
6. The inlet and outlet of the valve should be sealed with wax paper or plastic sheets to prevent dirt from entering.
7. The machined surface of valves that can rust in the atmosphere should be coated with anti rust oil to protect it.

8. Valves placed outdoors must be covered with waterproof and dustproof items such as felt or tarpaulin. The warehouse where valves are stored should be kept clean and dry.

Valve usage and maintenance
1. The purpose of use and maintenance is to extend the service life of the valve and ensure reliable opening and closing.
2. The valve stem thread often rubs against the valve stem nut and needs to be coated with a little yellow dry oil, molybdenum disulfide or graphite powder to provide lubrication. For valves that do not open and close frequently, it is also necessary to regularly rotate the handwheel and add lubricant to the valve stem threads to prevent seizing. For outdoor valves, a protective sleeve should be added to the valve stem to prevent rain, snow, dust, and rust.
3. If the valve system is mechanically inactive, add lubricating oil to the gearbox on time. Always keep the valve clean.
4. Regularly inspect and maintain the integrity of other components of the valve. If the fixed nut of the handwheel falls off, it should be matched and cannot be used properly, otherwise it will grind the four sides of the upper part of the valve stem, gradually losing the reliability of the fit, and even unable to start.
5. Do not rely on the valve to support other heavy objects, and do not stand on the valve.

6. The valve stem, especially the threaded part, should be regularly wiped, and the lubricant that has been contaminated by dust should be replaced with a new one because the dust contains hard debris, which can easily wear the thread and valve stem surface, affecting its service life.

Maintenance of valve packing
1. The packing is directly related to the key sealing components of whether leakage occurs when the valve is opened and closed. If the packing fails, causing leakage, the valve is also equivalent to failure, especially for valves in urea pipelines. Due to their high temperature, corrosion is more severe, and the packing is prone to aging. Strengthening maintenance can extend the lifespan of the filler.
2. When the valve leaves the factory, in order to ensure the elasticity of the packing, it is generally based on static pressure testing without leakage. After the valve is installed in the pipeline, due to temperature and other factors, external leakage may occur. At this time, it is necessary to tighten the nuts on both sides of the packing gland in a timely manner, as long as there is no leakage. If there is any external leakage in the future, tighten it again, and do not tighten it all at once to prevent the packing from losing elasticity and sealing performance.
3. Some valve packing contains molybdenum disulfide lubricating paste. After several months of use, corresponding lubricating grease should be added in a timely manner. When it is found that the packing needs to be supplemented, corresponding packing should be added in a timely manner to ensure its sealing performance.

Maintenance of valve transmission parts
During the opening and closing process of the valve, the lubricating grease originally added will continue to drain, and combined with factors such as temperature and corrosion, the lubricating oil will also continue to dry up. Therefore, the transmission part of the valve should be regularly inspected, and if oil shortage is found, it should be promptly replenished to prevent increased wear due to a lack of lubricant, resulting in inflexible transmission or failure of the casing.
Valve maintenance should be treated with a scientific attitude in order to achieve the expected results and application goals of valve maintenance work. In order to ensure normal production operation, reduce parking, and increase economic benefits, it is necessary to do the following three things well in terms of valves:
1.The correct selection of valves is the foundation.
2. Correct use of valves is crucial.
3. Proper maintenance is the guarantee.