Today, the editor will introduce to you the professional knowledge about pressure vessels.

Introduction to Pressure Vessels

Pressure vessel (y ā l ì r ó ng q ì), English: pressure vessel， It refers to a sealed equipment that contains gas or liquid and carries a certain pressure. In order to implement scientific management and safety supervision more effectively, China's "Pressure Vessel Safety Supervision Regulations" classify pressure vessels into three categories based on work pressure, medium hazard, and their role in production.

And different regulations have been made for the design, manufacturing process, inspection items, content, and methods of each category of pressure vessels. The pressure vessel has implemented the import commodity safety and quality permit system, and goods without an import safety and quality permit certificate are not allowed to be imported. It should be classified according to the latest TSG21-2016 "Safety Technical Supervision Regulations for Fixed Pressure Vessels", first divided into the first group of media and the second group of media according to the medium, and then classified into categories I, II, and III according to pressure and volume. The so-called first, second, and third categories in the old volume regulations are no longer applicable.

A pressure vessel is a sealed container that can withstand pressure. Pressure vessels have a wide range of applications and play an important role in many sectors such as industry, civilian use, military industry, as well as in many fields of scientific research. Among them, pressure vessels are most commonly used in the chemical and petrochemical industries, with pressure vessels used only in the petrochemical industry accounting for about 50% of the total number of pressure vessels. Pressure vessels are mainly used in the fields of chemical and petrochemical industries for processes such as heat transfer, mass transfer, and reaction, as well as for storing and transporting pressurized gases or liquefied gases; It is also widely used in other industrial and civilian fields, such as air compressors. All types of specialized compressors and auxiliary equipment for refrigeration compressors (coolers, buffers, oil-water separators, gas storage tanks, evaporators, liquid coolant storage tanks, etc.) are all pressure vessels.

2. Manufacturing process

(1) The manufacturing process of pressure vessels can generally be divided into: raw material acceptance process, marking process, cutting process, rust removal process, machining (including edge planing, etc.) process, rolling process, assembly process, welding process (product welding test plate), non-destructive testing process, hole marking process, overall inspection process, heat treatment process, pressure testing process, and anti-corrosion process.

(2) Different welding methods have different welding processes. The welding process is mainly determined based on the material, grade, chemical composition, welding structure type, and welding performance requirements of the welded parts. Firstly, it is necessary to determine the welding method, such as manual arc welding, submerged arc welding, tungsten inert gas welding, melting electrode gas shielded welding, etc. There are many types of welding methods that can only be selected based on specific circumstances. After determining the welding method, the welding process parameters are formulated. The types of welding process parameters are different, such as manual arc welding, which mainly includes: electrode model (or brand), diameter, current, voltage, welding power source type, polarity connection method, welding layer number, number of passes, inspection method, etc.