Definition of Pressure Vessels in Air Compressor Systems
In industrial production, the air compressor is the core equipment that supplies compressed air. Because compressed air poses potential energy‑release hazards, components in the system that operate under pressure must strictly comply with applicable regulations for special‑purpose equipment. Not all pressurized parts on an air compressor are classified as pressure vessels under the law; such classification is primarily determined by parameters such as the maximum working pressure, vessel volume, and the characteristics of the working medium.
Gas storage tank: the most critical pressure vessel component
In the air compressor system,Gas storage tankIt is the most typical and commonly encountered type of pressure vessel. Its primary functions are to store compressed air, dampen pressure fluctuations, reduce system temperature, and provide preliminary separation of moisture and impurities from the air.
According to the relevant national catalog of special equipment, when the maximum working pressure of a gas storage tank is greater than or equal to 0. 1MPa, and the product of pressure and volume is greater than or equal to 2. 5MPa ·L, when the working medium is a gas (including air), it falls under the scope of pressure vessel regulation. Consequently, the vast majority of industrial gas storage tanks are classified as statutory pressure vessels and must undergo rigorous registration, inspection, and management.
Oil–gas separator tank: a potential pressure vessel in screw compressors
In oil-injected screw compressors,Oil-gas separator tank(Commonly referred to as the oil–gas separator tank), it is also a critical pressure-bearing component. Its primary function is to separate the compressed oil–gas mixture, enabling the lubricating oil to return to the circulation system while delivering clean compressed air.
The oil‑gas separator tank also withstands the system’s operating pressure. If its design pressure, vessel volume, and process fluid conditions meet the criteria for pressure vessels as defined in the Special Equipment Catalog, then the oil‑gas separator tank is likewise classified as a pressure vessel. In practice, many large screw compressor units have oil‑gas separators with relatively large volumes, which are typically subject to regulatory oversight as pressure vessels.
Other pressure vessel components that may be involved
In addition to the air receiver and oil–water separator, certain components in the compressed air aftertreatment system may also qualify as pressure vessels under specific design conditions:
- Partial aftercooler: If the tube-side or shell-side design pressure‑volume product of the aftercooler meets the statutory criteria, and the medium is a gas or a liquefied gas, it may be classified as a pressure vessel.
- Gas–water separator and buffer tankIn complex compressed air distribution networks, if large-capacity buffer tanks or high-pressure air–water separators are installed and their operating parameters meet the relevant standards, they must also be managed as pressure vessels.
Key Points of Safety Management for Pressure Vessels
For air compressor components classified as pressure vessels, enterprises must strictly comply with applicable regulations during operation to ensure production safety.
- Periodic inspectionRegular inspections, including annual inspections and comprehensive examinations, must be reported to a specialized equipment inspection agency in accordance with the prescribed schedule; operation beyond the prescribed service life is strictly prohibited.
- Safety accessory verification: Equipped on the gas storage tank and oil separator tankSafety valveandPressure gaugeIt is an essential safety accessory and must be regularly calibrated to ensure its sensitivity and reliability.
- Daily InspectionOperators are required to periodically inspect the tank’s exterior for corrosion and deformation, check the connections for leaks, and drain the condensate from the tank on schedule to prevent accelerated internal corrosion.