Valve selection steps
1. According to the valve used in device or process piping, determine the working condition of the valve. For example, the working medium, working pressure and working temperature, etc. 2. According to the requirement of working medium, work environment, and users of valve sealing performance level. 3. Based on the purposes of the valve determine the type of valve and drive way. Types such as block valves, regulating valve, safety valve and other special valves, etc. Driving mode such as worm gear and worm, electric, pneumatic, etc. 4. According to the nominal parameters of valves. The determination of the nominal pressure, nominal size valves should match the process piping installation. Valve is in the process piping installation, therefore its use conditions should choose consistent with the design of the process piping, pipe adopted standards system and nominal pressure pipeline is determined, the valve nominal pressure, nominal size, adopted by the valve design and manufacturing standards can be identified. Some valves are rated time according to the medium flows through the flow valves or capacity to determine the nominal dimension of valve. 5. According to the actual operating condition of the nominal size of the valve and valve end face and the pipeline connection form. Such as flange, welding, or thread to the clamp. 6. According to the installation position of the valve, the installation space, nominal size to determine the structure of valve type. Such as non-rising stem gate valve, Angle valve, fixed ball valve, etc. 7. According to the characteristic of medium, working pressure and working temperature, to reasonably select correct valve shell and internal parts of the material.