Classification of pressure vessel categories and pressure grades

One: pressure vessel category division

1: Media grouping

The medium of the pressure vessel is divided into the following two groups, including gas, liquefied gas and liquid with high working temperature higher than or equal to the standard boiling point: (1) * group medium, the degree of toxicity is extremely hazardous, highly hazardous chemical medium, explosive Medium, liquefied gas. (2) The second group of media, except for the * group.

2: Media hazard

Medium hazard refers to the severity of occupational chronic hazards caused by accidents caused by accidents in the production process due to accidents caused by accidents, and the degree of toxicity and explosion hazard of the medium.

(1) Toxicity degree: Considering factors such as acute toxicity, high allowable concentration of Zui and occupational chronic hazard, the maximum allowable concentration of extreme damage is less than 0.1mg/m3~1.0mg/m3; the medium tolerance hui is high allowable concentration of 1.0mg/ M3~10.0mg/m3; the high hazard concentration of mild hazard is at or equal to 10.00mg/m3.

(2) Explosive medium: refers to an explosive mixture formed by mixing gas or liquid vapor, mist and air, and the lower explosion limit is less than 10%, or the difference between the upper explosion limit and the lower explosion limit is greater than or equal to 20%.

(3) Determination of the degree of toxicity of the medium and the degree of explosion hazard: determined according to HG20660-2000 "Classification of chemical medium toxicity hazard and explosion hazard degree in pressure vessels". HG20660 is not specified, the pressure vessel design unit refers to GB5044-85 "Occupational exposure to poison hazard classification" principle, determine the media group.

3: Pressure vessel classification method

(1) Basic division: The division of pressure vessel category should be based on the characteristics of the medium, select the classification diagram according to the following requirements, and then mark the coordinate points according to the design pressure p (unit MPa) and volume V (unit L) to determine the pressure vessel category. .

(2) Multi-chamber pressure vessel classification: multi-chamber pressure vessels (such as tube and shell of heat exchangers, jacketed vessels, etc.) are classified according to the category of high pressure chambers and are managed according to this category. However, the design and manufacturing technical requirements should be separately proposed according to the respective categories of each pressure chamber. The type of each pressure chamber is timed, the design pressure is taken from the design pressure of the pressure chamber, and the volume is taken from the geometric volume of the pressure chamber.

(3) Classification of multi-turn media pressure vessels in the same cavity: When there are multiple media in a pressure chamber, the categories are classified according to the medium with high group.

(4) Classification of pressure vessels with extremely small media content: When a hazardous substance is extremely small in the medium, it should be classified according to the degree of hazard and its content, according to the media group determined by the pressure vessel design unit.

(5) Classification of special cases

Two: pressure level division

The design pressure (p) of the pressure vessel is divided into four pressure levels of low pressure, medium pressure, high pressure and ultra high pressure: (1) low pressure (code L), 0.1 MPa ≤ p < 1.6 MPa; (2) medium pressure (code M) , 1.61MPa ≤ p < 10.0MPa; (3) high pressure (code H), 10.0MPa ≤ p < 100.0; (4) ultra high pressure (code U), p ≥ 100.0MPa.

Three: pressure vessel variety division

The pressure vessel is divided into a reaction pressure vessel, a heat exchange pressure vessel, a separation pressure vessel, and a storage pressure vessel according to the principle of action in the production process. The specific division is as follows:

(1) A reaction pressure vessel (code R) is mainly a pressure vessel for performing physical and chemical reactions of a medium, such as various reactors, a reaction vessel, a polymerization vessel, a synthesis tower, a shift furnace, a gas generator, and the like;

(2) a heat exchange pressure vessel (code E), mainly a pressure vessel for performing heat exchange of the medium, such as various heat exchangers, coolers, condensers, evaporators, etc.;

(3) Separation pressure vessel (code S), mainly used for pressure vessel for fluid pressure balance buffer and gas purification separation of the medium, such as various separators, filters, oil collectors, absorption towers, copper washing towers, Drying tower, stripper, sub-cylinder, deaerator, etc.; (4) Storage pressure vessel (code C, ball tank code B), mainly for pressure vessels for storing and containing gases, liquids, liquefied gases, etc. For example, various forms of storage tanks, buffer tanks, sterilizers, dyeing machines, dryers, steamers, and the like.

In a pressure vessel, if there are more than two principles of process function at the same time, the variety should be classified according to the main role in the process. (Wuxi Xinhui Biochemical Equipment Co., Ltd.)