National Standard for Compressor Vibration Levels

I. The Core Framework of Compressor Vibration Standards

As a core component of industrial power systems, the operational stability of compressors directly impacts production efficiency and safety. China has established a comprehensive national standards system for compressor vibration limits, primarily based on…GB/T (National Recommended Standard)The series serves as the core basis. Compressors of different structural types—such as reciprocating, screw, and centrifugal—and varying power ratings correspond to distinct vibration assessment criteria and acceptance limits in the standard.

National standards typically do not rely on a single fixed value; instead, they adopt a tiered management approach that takes into account the equipment’s rated speed, installation configuration, and vibration spectrum characteristics. The test environment must meet rigidity‑foundation requirements and eliminate interference from external piping stresses to ensure the reliability of data acquisition.

II. Definitions and Measurement Standards for Vibration Parameters

In the standard system, vibration assessment primarily relies on the following key parameters:

• Vibration Severity:Typically refers to the root-mean-square value of vibration velocity at a specified location on the bearing housing or machine casing (mm /s) is a core metric for assessing the overall health of the device.
• Vibration Displacement and Acceleration:Displacement is used to assess low-frequency mechanical looseness, while acceleration focuses on high-frequency bearing wear or abnormal gear meshing.
• Measurement point layout:The standard explicitly stipulates that sensors must be installed on both the drive end and the non-drive end in the horizontal, vertical, and axial directions, while avoiding areas with heat sources and strong electromagnetic interference.

Measuring instruments shall comply with the relevant metrological verification procedures, and the sampling frequency shall encompass the equipment’s fundamental frequency and its harmonic spectrum. Data recording is typically based on the average values obtained after the system has achieved stable continuous operation; transient spikes are excluded from routine acceptance criteria.

III. Limit Value Grading Logic for Common Machine Models

The limit values for compressors of different categories, as specified in the national standard, follow the principle of “class-based grading and speed‑based tiering”:

• Positive-displacement compressors (piston/screw):Particular attention is paid to vibrations caused by reciprocating inertial forces and rotor imbalance. Standards typically classify the acceptable range into three levels: new‑from‑factory, long‑term operation, and maintenance‑based early warning; the RMS value of the operating speed is generally kept below a specified threshold.
• Velocity-type compressors (centrifugal/axial-flow):Primarily governed by fluid‑dynamic stability, vibration limits are inversely proportional to the impeller diameter and the square of the rotational speed. The standard emphasizes the requirement for rapid passage through the critical‑speed region, while maintaining strict symmetry within the normal operating range.

In practical applications, enterprises are required to consult the specific tables in the latest version of the relevant product standard. When the standard does not impose mandatory requirements, the engineering community often relies on internationally recognized guidelines for evaluating mechanical equipment vibration to make analogous assessments.

IV. Common Causes of Excessive Vibration and Control Recommendations

When test data exceed the threshold of the standard limit, it is typically attributable to the following factors:

• Carbon deposits or scale buildup on rotor components can disrupt dynamic balance.
• Excessive coupling misalignment or loose anchor bolts
• Oil film instability in the lubrication system leads to oil whirl.
• Resonance occurs due to insufficient rigid support of the inlet and outlet piping.

To ensure equipment operates within compliance limits, it is recommended to establish a periodic vibration‑monitoring record. Routine maintenance should prioritize inspecting foundation bolt tightness and alignment accuracy, and regularly cleaning flow‑path components. For operating conditions characterized by frequent fluctuations, an online monitoring system can be implemented to provide trend‑based early warnings, thereby preventing cascading losses caused by unplanned shutdowns.

V. Conclusion

Strict adherence to national standards for compressor vibration levels is the foundation for ensuring long‑term, safe operation. Throughout all stages—equipment selection and acceptance, installation and commissioning, and operation, maintenance, and repair—technical personnel must follow the currently valid versions of the relevant standard documents. By combining standardized measurement methods with a scientifically sound preventive maintenance strategy, it is possible to effectively extend the service life of critical components and enhance the overall system efficiency.