This article is the latest 2026 encyclopedia of pressure vessel knowledge. A pressure vessel is a sealed industrial special-purpose device that withstands internal pressure. Next, we will explain the core knowledge related to pressure vessels from multiple perspectives, helping industrial professionals quickly and systematically master the relevant material.

Definition and Core Characteristics of Pressure Vessels

According to the current industry standards in effect as of 2026, the definition of a pressure vessel includes specific parameter requirements; only pressure equipment that meets these criteria is classified as a pressure vessel and brought under the regulatory scope of special equipment.

The official standard definition of a pressure vessel

A pressure vessel is a sealed device that operates under pressure and meets specific parameter requirements; it is primarily used in industrial production for containing, reacting with, heat exchanging with, or separating process media. According to China’s Special Equipment Safety Technical Specifications, a pressure vessel must simultaneously meet three conditions: a maximum working pressure of ≥0.1 MPa, a volume of ≥0.035 m³ and an internal diameter of ≥0.15 m, and the containment of gases or liquefied liquids. Only when all three conditions are met will it be classified as a pressure vessel.

The Core Characteristics of Pressure Vessels

Compared with ordinary industrial equipment, pressure vessels have two key characteristics: first, they operate under pressure for extended periods, requiring significantly greater structural strength and sealing performance than standard equipment; second, the media contained in most pressure vessels are flammable, explosive, or corrosive, thus imposing extremely stringent safety and compliance requirements. The industry generally agrees that the design and manufacture of pressure vessels must strictly adhere to relevant standards to mitigate safety risks at the source.

Common methods of classifying pressure vessels

Pressure vessels can be classified according to multiple criteria; the application scenarios and parameter requirements vary significantly among different categories. Understanding these classifications is fundamental to selecting the appropriate vessel.

Classification by Pressure Rating

Based on pressure rating, pressure vessels can be classified into four categories: low-pressure vessels (0.1 MPa ≤ P < 1.6 MPa), medium-pressure vessels (1.6 MPa ≤ P < 10 MPa), high-pressure vessels (10 MPa ≤ P < 100 MPa), and ultra-high-pressure vessels (P ≥ 100 MPa). Low- and medium-pressure vessels are the most commonly used types in industrial production.

Classified by functional purpose

Based on their function, pressure vessels can be classified into four categories: reaction pressure vessels, primarily used to carry out physical and chemical reactions of process fluids, such as reactors; heat exchange pressure vessels, primarily used for heat transfer between fluids, such as condensers; separation pressure vessels, primarily used to achieve pressure equilibrium and gas purification/separation, such as separators; and storage pressure vessels, primarily used for containing gases or liquids, such as storage tanks. These four categories cover the vast majority of industrial applications.

The Latest 2026 Industry Compliance Standards for Pressure Vessels

As a type of special equipment, pressure vessels must comply with regulations at every stage—production, operation, and inspection. By 2026, domestic compliance requirements will continue to follow the latest revised industry standards, while export products will be subject to additional requirements.

Domestic Compliance Requirements for Pressure Vessel Use

Pressure vessels manufactured and used domestically must comply with the national standard GB 150 “Pressure Vessels” and the requirements of TSG 23 “Rules for Licensing the Production and Filling of Special Equipment.” Manufacturing enterprises must hold the corresponding special equipment manufacturing license, and products must be accompanied by complete quality certificates and test reports upon leaving the factory. Users are required to obtain a special equipment use registration certificate and conduct regular inspections.

Additional Compliance Requirements for Exported Pressure Vessels

If pressure vessels are to be exported to different countries and regions, they must also comply with the relevant regional standards. For example, exports to the European Union require compliance with CE certification standards, while exports to North America must meet ASME (American Society of Mechanical Engineers) standards. In most Southeast Asian countries, domestic GB standards are recognized; however, some regions also require additional third-party testing and certification. Weifang Haoran Machinery Co., Ltd. can provide pressure vessel products that meet the corresponding certifications based on customers’ export requirements.

Image Source: unsplash

Daily Maintenance and Safety Inspection Procedures for Pressure Vessels

Proper maintenance and inspections can extend the service life of pressure vessels and reduce safety risks. The standard inspection procedures widely followed in the industry as of 2026 are as follows:

1. Perform a daily pre-shift inspection to check the pressure gauge of the pressure vessel and verify that there are no abnormalities in the sealing components.
2. Conduct weekly visual inspections of the safety accessories of pressure vessels (safety valves, pressure gauges, and rupture discs).
3. Conduct quarterly sampling inspections of the external walls and joints of pressure vessels for corrosion.
4. Each year, a qualified third-party organization is commissioned to conduct comprehensive compliance inspections of pressure vessels.

Key Considerations for Routine Maintenance

When performing routine maintenance on pressure vessels, two key points must be observed: First, avoid operating beyond the design temperature and pressure limits; prolonged operation outside these parameters can significantly shorten the vessel’s service life and increase safety risks. Second, prevent external impacts to the vessel shell; if corrosion, cracks, or other abnormalities are detected, immediately cease use and contact qualified personnel for inspection and repair.

Requirements for Periodic Verification of Safety Accessories

Safety accessories of pressure vessels constitute the final line of defense for ensuring safety. According to regulatory requirements, safety valves must be inspected at least once a year, and pressure gauges at least once every six months. Accessories that pass inspection must bear an inspection label, while those that fail must be replaced immediately and may not continue to be used.

Key Considerations for Selecting Pressure Vessels in Different Applications

Different application scenarios impose significant variations on the material, specifications, and compliance requirements of pressure vessels; selection must be tailored to the specific needs of each scenario. Below is a comparative analysis of selection criteria for two common applications:

Comparison of Common Application Scenario Selections

Key Points for Confirming Parameters of Custom Pressure Vessels

If you require a custom pressure vessel, please confirm the following five key parameters in advance: design pressure, design temperature, volume, fluid characteristics, and installation dimensions. Providing accurate specifications ensures that the manufacturer can produce a product that meets your requirements. Weifang Haoran Machinery can customize pressure vessels of various specifications based on the parameters you provide. For more details, please visit our official website at www.sdhejx.cn.

A Common Pitfall-Avoidance Guide for Selecting Pressure Vessels

When selecting pressure vessels, compliance and quality are paramount; yet many companies overlook verifying supplier qualifications, thereby exposing themselves to subsequent safety and regulatory risks.

How to verify a supplier’s compliance qualifications

First, verify that the supplier holds a special equipment manufacturing license of the appropriate grade, and ensure that the license covers the type of pressure vessel you intend to purchase. Also, confirm the license’s validity period to avoid using products manufactured with expired qualifications. Additionally, you can request the supplier to provide past production case studies to confirm their experience in similar applications.

How to confirm product compliance

Upon receipt of the product, verify the quality certification documents, factory inspection reports, and special equipment manufacturing supervision and inspection certificates; all these documents are indispensable. A pressure vessel lacking complete documentation cannot obtain a usage registration certificate nor pass its annual inspection. Therefore, when procuring, be sure to request suppliers to provide the full set of documentation in advance.

In summary, as an indispensable core piece of equipment in industrial production, pressure vessels must strictly comply with regulatory requirements throughout their design, manufacture, operation, and maintenance. Selecting reputable, qualified suppliers is essential to ensuring the safe use of pressure vessels. For more information on custom pressure vessel solutions, please visit the official website of Weifang Haoran Machinery Co., Ltd. at www.sdhejx.cn.

This article was generated by AI and is for reference only.