Does this type of container belong to pressure vessels?

It falls under the category of pressure vessels, and the assessment is complete^_^ – Reason: The pressure in the pipe system is 0.4 MPa. However, since not all the conditions required for classifying it as a pressure vessel regulated by relevant standards are met, it is impossible to determine whether it indeed belongs to this category. It is recommended that the original poster think carefully about what they want to ask before posing the question, so that everyone can provide you with adequate assistance!

The properties of styrene are as follows: it is a colorless and transparent oily liquid with a density of 0.9074 g/cm3. Melting point -31°C. Boiling point 146°C. Flash point 31.3°C. Autoignition point: 490°C. Soluble in alcohol and ether, insoluble in water. It burns very easily when exposed to an open flame. It polymerizes easily upon heating, exposure to light, or in the presence of peroxide catalysts, releasing heat and leading to an explosion. It reacts violently with chlorosulfonic acid, fuming sulfuric acid, and concentrated sulfuric acid, posing an explosion risk. Toxic; it is irritating to human skin, eyes, and respiratory system. The maximum allowable concentration in the air is 100 ppm. The explosive limit is 1.1–6.1%. The fluid in the equipment’s tube side is styrene, with a pressure of 0.4 MPa. Based on container classification, it can be determined to be a pressure vessel; however, the information available is not sufficient to determine exactly which category it belongs to.

Strictly speaking, it is not a pressure vessel, as it does not meet the definition of a pressure vessel

Based on the conditions you provided, it does not fall under the category of pressure vessels

It must be a pressure vessel; the fluid flowing within the tubes of this equipment is styrene. According to the \"Classification of Chemical Media in Pressure Vessels Based on Their Hazard and Explosion Risk Levels,\" styrene is considered a medium-hazardous medium. The volume inside the tubes is insufficient, and the pressure is 0.4 MPa. If P*V is greater than or equal to 10 MPa·m3, it would be classified as category three. However, due to insufficient information, it is not possible to determine its exact classification.

Definition of pressure vessels: 1. The maximum operating pressure is greater than or equal to 0.1 MPa (excluding hydrostatic pressure); 2. The inner diameter (for non-circular cross-sections, it refers to the largest dimension) is greater than or equal to 0.15 m, and the volume is greater than or equal to 0.025 m³. 3. The medium contained is a gas, a liquefied gas, or a liquid whose maximum operating temperature is higher than or equal to its standard boiling point.

The scope of pressure vessels should be determined in accordance with the Regulations on the Safety Supervision of Special Equipment; what was mentioned above refers to the scope covered by those regulations, and there are slight differences between the two

This device is a pressure vessel; no specific dimensions/volume are given, making it difficult to classify

It is a heat exchange device; it’s not clear what type it is. If it is of the shell-and-tube type, it is necessary to determine whether it should be classified as a pressure vessel based on its volume and the product of that volume and the design pressure, in accordance with the relevant regulations on pressure vessels； If it is a sleeve type, it does not fall under pressure vessels and is regulated as a pressure pipeline.

Study hard*, thanks to everyone above

The equipment design data is incomplete, making it impossible to determine； Judging solely based on a pressure of 0.4 MPa is too arbitrary.

The concept of pressure vessels is broad; in a general sense, any sealed container that holds pressurized media is referred to as a pressure vessel. When people ask about pressure vessels, they are usually referring to those that are subject to regulatory oversight; these are what are commonly known as \"regulated pressure vessels\". Therefore, those of us in this industry should ask more specifically: whether it is a vessel that is subject to regulatory oversight, in other words, whether it is a regulated pressure vessel. We shouldn’t ask in such a general manner whether it is a pressure vessel.

What is the design temperature of the pipeline? If it exceeds the boiling point, it must undoubtedly be a pressure vessel.

Agreed. The conditions are not met; it’s unclear whether it falls under regulatory oversight

Is the heat exchanger of the shell-and-tube type, with end caps? If so, it must belong to a pressure vessel.

It depends on the design pressure of the equipment to determine it

I think it belongs to pressure vessels. The reason is as follows: A pressure vessel, in English, refers to a sealed device that holds gases or liquids and is subjected to a certain pressure. Storage and transportation containers, reaction vessels, heat exchange vessels, and separation vessels all fall under pressure vessels. Table of Contents Overview Scope of Application of the Safety Technical Inspection Regulations for Fixed Pressure Vessels Overview of Classification Classification in China Manufacturing Processes Specific Provisions for Classification Grouping of Media Hazard Level of Media Classification Methods Classification of Pressure Levels Classification of Types of Pressure Vessels Relevant Regulations and Standards Other Information Inspections External Inspection of Pressure Vessels Internal and External Inspections of Pressure Vessels Comprehensive Inspections of Pressure Vessels Precautions for Use and Routine Maintenance of Pressure Vessels Operating Conditions Pressure Temperature Media Reasons for High Accident Rates among Pressure Vessels Technical Requirements Management of Use Examples of Pressure Vessel Applications – Reactors Stainless Steel Reactors Glass-Lined Reactors Magnetic Stirring Reactors Causes and Prevention of Deformation in Pressure Vessel Manufacturing The “Pressure Vessels” Magazine Expand Overview Scope of Application of the Safety Technical Inspection Regulations for Fixed Pressure Vessels Overview of Classification Classification in China Manufacturing Processes Specific Provisions for Classification Grouping of Media Hazard Level of Media Classification Methods Classification of Pressure Levels Classification of Types of Pressure Vessels Relevant Regulations and Standards Other Information Inspections External Inspection of Pressure Vessels Internal and External Inspections of Pressure Vessels Comprehensive Inspections of Pressure Vessels Precautions for Use and Routine Maintenance of Pressure Vessels Operating Conditions Pressure Temperature Media Reasons for High Accident Rates among Pressure Vessels Technical Requirements Management of Use Examples of Pressure Vessel Applications – Reactors Stainless Steel Reactors Glass-Lined Reactors Magnetic Stirring Reactors Causes and Prevention of Deformation in Pressure Vessel Manufacturing The “Pressure Vessels” Magazine Expand Editor’s Note Overview Scope of Application of the Safety Technical Inspection Regulations for Fixed Pressure Vessels General Provisions 1.3: These regulations apply to pressure vessels that meet all of the following conditions; in other words, only those that satisfy these conditions can be classified and subject to supervision. 　　(1) The operating pressure (Note 1) is greater than or equal to 0.1 Mpa (operating pressure refers to the highest pressure that may be reached at the top of the pressure vessel under normal operating conditions (gauge pressure); hydrostatic pressure is not included). (2) Vessels with an inner diameter of not less than 150 mm, where for non-circular cross-sections this refers to the width, height, or diagonal – for example, the diagonal in the case of a rectangle and the major axis in the case of an ellipse) ； 　　(3) The working medium is a gas, liquefied gas, or a liquid with a temperature higher than its standard boiling point ； 　　Introduction to Use: Pressure Vessels Pressure vessels have a wide range of applications. It is a device that plays an important role in various sectors of the national economy, such as the petrochemical industry, energy industry, scientific research, and the military industry. A pressure vessel generally consists of six main parts that make up its body: the cylinder, the end caps, flanges, sealing elements, openings and connections, as well as supports. In addition, it is equipped with safety devices, meters, and internal components that function according to completely different manufacturing processes. Due to reasons such as sealing, pressure resistance, and the type of medium contained, pressure vessels are prone to explosions and fires, which can endanger the safety of people, equipment, and property as well as cause environmental pollution. Currently, countries around the world consider it an important product subject to supervision and inspection, with **designated specialized agencies carrying out such supervision, inspection, and technical testing in accordance with** established regulations and standards. Edit this section: Classification overview. There are many ways to classify pressure vessels; from the perspectives of use, manufacturing, and inspection, the following classifications exist. Pressure vessels (1) are classified according to the pressure level they can withstand into low-pressure vessels, medium-pressure vessels, high-pressure vessels, and ultra-high-pressure vessels. 　　(2) Classified by the medium contained: non-flammable, non-toxic ； Flammable or toxic ； Highly toxic. 　　(3) Classified according to their functions in the process: 　　① Reaction vessel: A container used to carry out physical and chemical reactions of the medium. 　　②Heat exchange vessel: A vessel used to facilitate heat exchange between fluids. 　　③Separation vessel: A vessel used to facilitate mass exchange of media, gas purification, and the separation of solids, liquids, and gases. 　　④Storage and transportation containers: Containers used to hold liquid or gaseous materials, storage and transportation media, or to provide pressure-balancing and cushioning functions. Classification in China 　To enable more effective scientific management and safety inspections, China’s ‘Regulations on the Safety Inspection of Pressure Vessels’ classify pressure vessels into three categories based on working pressure, the hazard level of the medium involved, and their role in production. Different regulations are set for pressure vessels in each category regarding their design and manufacturing processes, as well as the inspection items, contents, and methods. A safety and quality licensing system for imported goods has been implemented for pressure vessels; goods without an import safety and quality license are not allowed to be imported. Classification should be carried out in accordance with the latest TSG R0004-2009 \"Regulations on Safety Supervision of Fixed Pressure Vessels.\" First, the media are divided into Group 1 media and Group 2 media, and then categories I, II, and III are determined based on pressure and volume. The so-called Category 1, Category 2, and Category 3 under the old regulations are no longer applicable. Edit this section: Manufacturing process 1. The manufacturing processes for pressure vessels can generally be divided into: raw material inspection, marking, cutting, rust removal, machining (including edge planing, etc.), rolling, assembly, welding (welding test plates for the product), non-destructive testing, hole marking, final inspection, heat treatment, pressure testing, and anti-corrosion treatment. 　　2. Different welding methods have different welding processes. The welding process is primarily determined by the material, grade, and chemical composition of the workpieces to be welded, the type of structure of the welded parts, and the required welding properties. First, it is necessary to determine the welding method, such as shielded metal arc welding, submerged arc welding, tungsten inert gas welding, gas metal arc welding, and so on. There are many types of welding methods, and the choice must be made based on the specific circumstances. After determining the welding method, the welding process parameters are established. There are various types of such parameters; for example, in manual arc welding, they mainly include: electrode type (or grade), diameter, current, voltage, type of welding power supply, polarity configuration, number of welding layers, number of passes, inspection methods, and so on. Editorial: Specific provisions for classification – Medium grouping. The media used in pressure vessels are divided into the following two groups: gases, liquefied gases, or liquids whose maximum operating temperature is equal to or higher than their standard boiling point. 　　(1) First group of media: Chemical media with extreme or high toxicity, explosive media, and liquefied gases. 　　(2) Second group of media: Media other than those in the first group. Hazardity of the medium: The hazardality of a medium refers to the severity of potential risks associated with large-scale contact between the medium and human bodies as a result of accidents during the production process of pressure vessels, including explosions, or chronic occupational hazards caused by frequent leaks. It is expressed in terms of the toxicity level of the medium and the degree of explosion risk. 　　A1.2.1 Degree of toxicity: Taking into account factors such as acute toxicity, maximum allowable concentration, and chronic occupational hazards. The highest permissible concentration for extreme hazard is less than 0.1 mg/m3 ； For highly hazardous substances, the maximum allowable concentration is 0.1–1.0 mg/m3; for moderately hazardous substances, it is 1.0–10.0 mg/m3; for slightly hazardous substances, it is 10.0 mg/m3 or higher. 　　A1.2.2 Explosive media: Refer to substances formed by the mixture of gases or liquid vapors/mists with air, whose lower explosion limit is less than 10%, or whose difference between the upper and lower explosion limits is 20% or more. 　　A1.2.3 The specific toxicity hazards and explosion risks of media are determined in accordance with the two standards: GB 5044—1985 \"Classification of Hazards from Occupational Exposure to Toxic Substances\" and HG 20660—2000 \"Classification of Toxicity Hazards and Explosion Risks of Chemical Media in Pressure Vessels\". When the two are inconsistent, the one with a higher level of harm (risk) shall prevail. Edit this section: Classification method Basic classification The classification of pressure vessels should first be carried out based on the properties of the medium; the appropriate classification chart should be selected according to the following requirements. Then, by using the design pressure p (in MPa) and volume V (in L), a coordinate point is determined to identify the category of the vessel: (1) For the first group of media, the classification of pressure vessels is shown in Figure A-1. 　　(2) For the second group of media, the classification of pressure vessels is shown in Figure A-2. 　　Figure A-1: Classification chart of pressure vessels – Group 1 media Figure A-2: Classification chart of pressure vessels – Group 2 media Classification of multi-chamber pressure vessels Multi-chamber pressure vessels (such as the tube side and shell side of heat exchangers, jacketed vessels, etc.) are classified according to the highest-pressure chamber present, and are managed based on that classification. However, design and manufacturing technical requirements should be specified separately for each pressure chamber according to its own category. When categorizing each pressure chamber, the design pressure is taken as that of the respective chamber, and the volume is taken as its geometric volume. 　　1. Classification of containers with multiple media in the same chamber When there are multiple media within a pressure chamber, they are classified according to the medium with the highest grade. 　　2. Classification of containers with extremely low media content When the concentration of a hazardous substance in the medium is extremely low, it is necessary to consider both its degree of hazard and its concentration; the media category shall be determined by the pressure vessel design unit. 　　Classification for special cases: (1) When the coordinate point lies on the classification line in Figure A-1 or Figure A-2, it is classified according to the higher category. 　　(2) For media that are not explicitly specified in GB 5044 and HG 20660, the media category shall be determined by the pressure vessel design unit based on a comprehensive consideration of their chemical properties, degree of hazard, and concentration. (3) Pressure vessels falling within the scope of Article 1.4 of these regulations are uniformly classified as Class I pressure vessels. Pressure class classification The design pressure (p) of pressure vessels is divided into four pressure classes: low pressure, medium pressure, high pressure, and ultra-high pressure: (1) Low pressure (code L): 0.1MPa ≤ p