Are there any special-purpose devices in a screw-type air compressor?

Equipment characteristics of the screw-type air compressor host unit

The compressor unit of a screw-type air compressor is not classified as special equipment. Its primary function is to compress atmospheric air into high-pressure air through mechanical motion. Under the current catalog of special equipment, standalone air-compression machinery is not subject to the regulatory framework for special equipment. Consequently, when procuring and installing an air compressor unit, enterprises are not required to follow the procedures for reporting and registering such equipment as special machinery.

Special equipment components in the air compressor system

Although the air compressor host is not classified as special equipment, a complete compressed-air system typically comprises multiple components, some of which fall under the regulatory scope of special equipment.

• Gas storage tankThis is the most common type of special equipment in compressed-air systems. Air receivers are used to store compressed air and stabilize pipeline pressure. Depending on their volume and design pressure, they are typically classified as stationary pressure vessels or simple pressure vessels. Air receivers that meet specific regulatory criteria must be registered as special equipment and undergo periodic inspections.
• Pressure pipeline: If the compressed air transmission pipelines in a system meet specific pressure, diameter, and medium‑related criteria, they may also fall under the regulatory scope of pressure piping for special equipment.

Verification Requirements for Safety Accessories

In compressed air systems, the management of safety accessories is equally critical. These components fall under the category of special‑equipment safety devices and must be subject to stringent oversight:

• Safety valve: Installed on gas storage tanks or system pipelines, it is used for overpressure relief. Safety valves must be periodically inspected and calibrated by a qualified organization to ensure their set pressure is accurate and reliable.
• Pressure gauge: Used for monitoring system pressure. Pressure gauges are mandatory‑calibration measuring instruments and must undergo periodic verification or calibration to ensure accurate readings.

Corporate Compliance Management Recommendations

To ensure production safety and compliance with applicable regulations, enterprises should pay attention to the following points when operating screw-type air compressor systems:

• Define equipment boundariesDuring the equipment procurement and installation phases, carefully verify the system configuration to determine which components qualify as special‑purpose equipment and which are simple pressure vessels exempt from certain inspection procedures.
• Establish ledgers and systems: Establish dedicated management records for special equipment such as gas storage tanks in the system, and develop operating procedures and emergency response plans.
• Implement regular inspections.: In strict accordance with the requirements of relevant safety technical specifications, submit applications for periodic inspections of special equipment in advance and ensure that all safety accessories are used within their valid service life.