1. Clarify the purpose of the valve in the equipment or device
Determine the working conditions of the valve: the nature of the applicable medium, the working pressure, the working temperature and the control method.
2. Correctly select the type of valve
The correct choice of valve type is a prerequisite for the designer to fully grasp the entire production process and operating conditions. When selecting the valve type, the designer should first grasp the structural characteristics and performance of each valve.
3. Determine the end connections of the valve
Among threaded connections, flange connections, and welded end connections, the first two are the most commonly used. Threaded valves are mainly valves with a nominal diameter below 50mm. If the diameter is too large, the installation and sealing of the connecting part will be very difficult. Flanged valves are more convenient to install and disassemble, but they are heavier and more expensive than threaded valves, so they are suitable for pipeline connections of various diameters and pressures. Welded connections are suitable for heavy loads and are more reliable than flanged connections. However, it is difficult to disassemble and reinstall the valve connected by welding, so its use is limited to the occasions where it can usually run reliably for a long time, or where the conditions of use are severe and the temperature is high.
4. Selection of valve material
When selecting the material of the valve shell, internal parts and sealing surface, in addition to considering the physical properties (temperature, pressure) and chemical properties (corrosiveness) of the working medium, the cleanliness of the medium (with or without solid particles) should also be grasped. In addition, it is necessary to refer to the relevant regulations of the state and the user department. Correct and reasonable selection of valve material can obtain the most economical service life and best performance of the valve. The valve body material selection sequence is: cast iron-carbon steel-stainless steel, and the sealing ring material selection sequence is: rubber-copper-alloy steel-F4.
5. Other
In addition, the flow rate and pressure level of the fluid flowing through the valve should also be determined, and the appropriate valve should be selected using the existing data (such as valve product catalogs , valve product samples, etc.).
Post time: May-11-2022
