A pressure vessel is a closed device that holds gas or liquid and bears certain pressure. In order to more effectively implement scientific management and safety supervision, the pressure vessels are divided into three types according to working pressure, medium harmfulness and their role in production in the "pressure vessel safety supervision Rules".

And for each type of pressure vessels in the design, manufacturing process, as well as inspection items, content and way to make different provisions. Pressure vessels have implemented a safety and quality licensing system for imported commodities, and commodities without import safety and quality licensing certificates are not allowed to be imported.

Manufacturing process:

Different welding methods have different welding processes. The welding process is mainly determined according to the material, grade, chemical composition, structure type and welding performance requirements of the welder.

First of all, we should determine the welding method, such as hand arc welding, submerged arc welding, tungsten argon arc welding, MIG welding and so on. There are many kinds of welding methods, which can only be selected according to the specific situation. After the welding method is determined, the welding process parameters are formulated.

The types of welding process parameters are different, such as hand arc welding mainly include: electrode model (or brand), diameter, current, voltage, welding power supply type, polarity connection method, welding layer number, number of channels, inspection method and so on.

When the medium in the pressure vessel is a mixed substance, the degree of toxicity of the medium or whether it belongs to flammable medium should be determined by the process design department of the designing unit or the production technology department of the using unit according to the composition of the medium and the division principle of the degree of toxicity or flammable medium.

Corrosive medium, petrochemical medium to pressure vessel materials have corrosion resistance requirements. Sometimes because there are impurities in the medium, the corrosion is aggravated. The types and properties of corrosive media are not the same, and the process conditions are different, the corrosion of the medium is not the same. This requires the pressure vessel in the selection of materials, in addition to should meet the mechanical properties under the conditions of use, but also have enough corrosion resistance, if necessary, but also take certain anti-corrosion measures.

The above content reference: Baidu Baike - pressure vessel