A container that meets the following three conditions simultaneously can be called a pressure vessel:
The working pressure is greater than or equal to 0.1 MPa (Note 1-2);
The volume is greater than or equal to 0.03 m3 and the inner diameter (non-circular section refers to the geometric dimension of the inner boundary of the section) is greater than or equal to 150 mm (Note 1-3);
The medium used is gas, liquefied gas, and liquid with a higher working temperature than or equal to its standard boiling point (Note 1-4).
Note 1-2: Working pressure refers to the higher pressure (gauge pressure) that may be reached at the top of a pressure vessel under normal working conditions.
Note 1-3: Volume refers to the geometric volume of a pressure vessel, calculated from the dimensions indicated on the design drawings (without considering manufacturing tolerances) and rounded. Generally, the volume of the internal components connected to the pressure vessel needs to be deducted.
Note 1-4: When the medium inside the container is a liquid with a high working temperature lower than its standard boiling point, if the volume of the gas phase space is greater than or equal to 0.03 m3, it also falls within the scope of application of this regulation.
Classification of pressure levels
The design pressure (p) of pressure vessels is divided into four pressure levels: low pressure, medium pressure, high pressure, and ultra-high pressure:
(1) Low pressure (code L) 0.1MPa ≤ p<1.6MPa
(2) Medium pressure (code M) 1.6MPa ≤ p<10.0MPa
(3) High pressure (code H) 10.0MPa ≤ p<100.0MPa
(4) Ultra high pressure (code U) p ≥ 100.0MPa.
Variety classification
Pressure vessels are divided into reaction pressure vessels, heat exchange pressure vessels, separation pressure vessels, and storage pressure vessels according to their operating principles in the production process. The specific division is as follows:
(1) Reaction pressure vessel (code R): It is mainly used as a pressure vessel for completing physical and chemical reactions of media, such as reactors, reaction vessels, decomposition pots, sulfurization tanks, decomposition towers, polymerization pots, high-pressure reactors, ultra-high pressure reactors, synthesis towers, transformation furnaces, steaming pots, steaming balls, steaming kettles, gas generators, etc.
(2) Heat exchange pressure vessel (code E): mainly used for heat exchange of media, such as shell and tube waste heat boilers, heat exchangers, coolers, condensers, heaters, disinfection pots, dyers, dryers, steaming and frying pots, preheating pots, solvent preheaters, steamers, steamers, electric steam generators, gas generators, water jackets, etc.
(3) Separation pressure vessel (code S): It is mainly used to achieve fluid pressure balance buffering and gas purification separation of media, such as separators, filters, oil collectors, buffers, scrubbers, absorption towers, copper washing towers, drying towers, stripping towers, steam separators, oxygen removers, etc.
(4) Storage pressure vessel (code C, including ball tank code B): It is mainly used as a pressure vessel for storing and containing gases, liquids, liquefied gases and other media, such as various types of storage tanks.
In a pressure vessel, if there are two or more process principles at the same time, the varieties should be classified according to the main functions in the process.
