What Factors Determine The Working Conditions Of Sanitary Valves?
What factors does the working condition of Sanitary Valve depend on?
The working conditions of sanitary valves depend on many factors, including: the working pressure of the medium, the working temperature, the characteristics of the medium, the changes in pressure and temperature, the driving mode, the installation position of the sanitary valve, the maintenance cycle,
The working conditions of sanitary valves depend on many factors, including: the working pressure of the medium, the working temperature, the characteristics of the medium, the changes in pressure and temperature, the driving mode, the installation position of the valve, the maintenance cycle, whether the middle cavity needs pressure relief, whether it has a fireproof structure, whether it has an anti-static structure, whether it needs grease injection, whether the sanitary valve is buried, whether it is installed on land or offshore, whether it is adjusted or opened and closed, and the environmental conditions of the valve.
Generally speaking, the higher the working pressure and temperature of the sanitary valve, the worse the working conditions will be when it is installed offshore. Therefore, in order to ensure the safety and reliability of the valve, the pressure-bearing parts and pressure-control parts of the valve need to have sufficient strength, especially the various properties of the material at high and low temperatures, such as thermal strength, oxidation resistance, thermal stability, and impact toughness of the material under low temperature conditions. The sealing surface material must also have good resistance to scratches, wear, corrosion, and erosion, because the high-pressure medium flows through the sealing surface very quickly and erosion is serious. In order to ensure the sealing performance of the packing and the gasket, different forms and materials must be selected according to the medium characteristics, temperature, and working pressure. As for valves working at low and ultra-low temperatures, it must be ensured that the material should have sufficient low-temperature impact toughness. For valves working in corrosive media, all pressure-bearing parts and pressure-controlling parts (including gaskets and packing) in contact with the medium should have sufficient stability against the chemical action of the medium, otherwise the valve will not be corrosion-resistant and have a short service life and cannot meet the use requirements.
Pressure and temperature fluctuations will cause poor sealing conditions for the connecting flange, because the connecting bolts and gaskets will deform when the working pressure and working temperature are high. When the working pressure and working temperature are reduced, the gasket loses its sealing performance due to insufficient clamping force. Such periodic fluctuations also affect the material properties of the parts. Therefore, fluctuations in working pressure and working resistance are extremely unfavorable to the working conditions of the valve.
Each drive device has its own force characteristics, which are related to the different specific pressure values on the sealing surface, and also to the stress of the valve stem, valve stem nut and other parts. When the electric device is closed to the end point, it will cause impact load on the sealing surface, especially for the stop valve. The hydraulic device is usually a relatively stable load, and the pneumatic device will also have an impact load on the stop valve. In the safety valve, when the valve disc returns to the seat, the sealing surface will also be impacted due to the action of the spring and the heavy hammer. The state of the sealing surface deteriorates and the service life of the valve is affected to varying degrees.
When sanitary valves are installed and used in the open air, the working conditions are very poor. Because it is easy to rust due to wind and rain, and sometimes even destroys lubrication. If dust and sand fall into the joints of the parts, it will accelerate the wear of the parts. If the valve is installed and used at sea, the working environment of the valve will be even worse. The valve as a whole is in salt spray and will be corroded by chloride ions in the salt spray. The valve is very easy to rust and lose its function. The material selection of the valve should consider the corrosion resistance of chloride ions, and the painting of the outer surface should also be paid attention to. If the valve is buried for installation, a fully welded valve with an extension should be selected to prevent the valve from being corroded by groundwater and mud after being buried, which may damage the valve's connecting parts and moving parts.
In order to ensure the service life of sanitary valves, the structure of the valve and the materials of the main parts must be selected according to the working conditions, otherwise the valve life will inevitably be reduced. At the same time, the maintenance of the valve should be strengthened during use. For example, regular cleaning of dirt, regular grease injection, regular maintenance, etc., to extend the service life of the valve.
