Answer: Different users have different requirements for air source quality. GB/T 13277-1991《General Compressed Air Quality Grades》was formulated for this purpose. This standard stipulates the amount of solid particles, moisture and oil content in compressed air.
In a broader sense, a good air source should also have stable pressure during use and minimize pollution to the surrounding environment.
(1) Method of expressing compressed air quality grades. Compressed air quality grades are represented by three Arabic numerals. If there is no requirement for a certain pollutant level, "一" is used instead.
Example: 4, 6, 5 means that the solid particle size and concentration in the compressed air are 4 levels, the water vapor content is 6levels, and the oil content is 5 levels.
(2) Quality grades.
1) Solid particles. The grades of solid particle size and concentration are shown in Sheet 1-1.
|
Level |
Maximum particle size (μm) |
Maximum concentration (mg/m³) |
|
1 |
0.1 |
0.1 |
|
2 |
1 |
1 |
|
3 |
5 |
5 |
|
4 |
40 |
1 |
2)The water vapor content in the air is expressed as pressure dew point. The pressure dew point levels are shown in Sheet1-2.
Sheet 1-2 Pressure dew point levels
|
Level |
Maximum pressure dew point (℃) |
Level |
Maximum pressure dew point (℃) |
|
1 |
-70 |
4 |
3 |
|
2 |
-40 |
5 |
7 |
|
3 |
-20 |
6 |
10 |
NOTE:When lower pressure dew points are required, they must be specified.
3)Total oil volume (including oil droplets, suspended particles, and oil vapor) and oil content levels are shown in Sheet1-3.
Sheet 1-3 Total oil content (including oil droplets, suspended particles, and oil vapor) Oil content level
|
Level |
Maximum oil content(mg/m³) |
Level |
Maximum oil content(mg/m³) |
|
1 |
0.01 |
4 |
5 |
|
2 |
0.1 |
5 |
25 |
|
3 |
1 |
|
|
Note: Oil content refers to absolute pressure 0.1MPa and temperature 20
.
