What is the compressed air standard for general industrial use?

The standard of oil content of compressed air for general industrial use is usually not exceeding 0.01 mg per cubic metre (ISO 8573-1 Class 1 or GB/T 13277.1-2023 Class 1), some scenes can be relaxed 0.1 mg (Grade 2). The following are specific instructions:

1. International Standard (ISO 8573-1)

ISO 8573-1 divides compressed air quality into several levels, of which the oil content levels are as follows:

• level 0: Residual oil content defined by equipment user or supplier (better than grade 1).
• Level 1: ≤ 0.01 mg/m & sup3;(suitable for high-precision scenarios, such as electronics, pharmaceutical, and food industries).
• Level 2: ≤ 0.1 mg/m & sup3;(applicable to general industrial scenarios, such as instrument gas and pneumatic tools).
• Level 3: ≤ 1 mg/m & sup3;(suitable for scenes with low sensitivity to oil, such as miscellaneous pneumatic equipment).

Domestic 2. Standards (GB/T 13277.1-2023)

the domestic standard corresponds to ISO 8573-1 and specifies the oil content level of compressed air:

• level 1: ≤ 0.01 mg/m & sup3;(consistent with ISO level 1, suitable for demanding scenarios).
• Level 2: ≤ 0.1 mg/m & sup3;(consistent with ISO level 2, suitable for general industrial scenarios).
• Grades 3-6: Oil content is gradually relaxed, but it is less used in industrial applications.

3. key application scenarios and oil content requirements

1. high Precision Scenarios:
   • electronics, semiconductor, pharmaceutical, food industry compressed air of grade 1(≤ 0.01 mg/m & sup3;) is required to avoid oil contamination of the product or equipment.
   • Example: Chip packaging, pharmaceutical production, food packaging, etc.
2. General industrial scenario:
   • instrument gas, pneumatic tools, painting, air bearings: Class 2(≤ 0.1 mg/m & sup3;) compressed air can be used to balance cost and performance.
   • Example factory miscellaneous pneumatic equipment, ash removal system, etc.
3. Scene not sensitive to oil:
   • pneumatic fixture, stamping equipment, purging process: Class 3(≤ 1 mg/m & sup3;) compressed air can be used to further reduce costs.

4. oil content control measures

1. selection of air compressor:
   • oil-free air compressor: Directly generate oil-free compressed air, suitable for level 1 scenarios.
   • Oil-injected screw air compressor: Multi-stage filtration (e. g. coalescing filter, activated carbon adsorption tank) is required to reduce the oil content to grade 2 or lower.
2. Post-processing equipment:
   • coalescing filter: Removing liquid oil and oil aerosols can reduce the oil content to ≤ 1 mg/m & sup3;.
   • Activated carbon adsorption tank: Further remove oil vapor and meet the requirements of level 1 (≤ 0.01 mg/m & sup3;).
3. Regular inspection and maintenance:
   • use a compressed air quality detector to regularly check for oil content, water content and particulate matter.
   • Visually check the spread of oil spots after compressed air is introduced into purified water, or check the blue fluorescence on the filter paper by ultraviolet lamp.