Industrial pipeline valves can be divided into vacuum valves, low-pressure valves, medium-pressure valves, high-pressure valves, and ultra-high-pressure valves according to their nominal pressures; valves can be divided into normal temperature valves, medium temperature valves, high temperature valves, and low temperature valves according to their working temperature.
Valves can also be classified according to the type of drive device, the connection method with the pipeline, and the material used for the valve body. Valves can be named individually or in combination according to various classification methods, and can also be named according to the structural features or specific uses of the opening and closing parts.
The basic parameters of the valve are working pressure, working temperature and caliber. For various valves widely used in industrial pipelines, nominal pressure and nominal diameter are commonly used as basic parameters. Nominal pressure refers to the maximum working pressure that a valve of a certain material can withstand at a specified temperature. Nominal diameter refers to the nominal inner diameter of the connecting end of the valve body and the pipe.
Valves have different requirements according to their types and uses, mainly including sealing, strength, adjustment, circulation, opening and closing performance. In the design and selection of valves, in addition to the basic parameters and performance, the performance of the fluid must also be considered, including the phase state of the fluid (gas, liquid or solid particles), corrosiveness, viscosity, toxicity, flammability and explosiveness , Preciousness, rarity, radioactivity, etc.