QC/T 1133-2020Safety elements of air filters for commercial vehicles (English PDF)

4.6 Flame-retardancy

For filter elements used in special occasions (such as natural gas engines, etc.), the flame-retardancy of the filter material used shall meet the following requirements:

a) The average continuous burning time is not more than 5 s;

b) The average carbonization length is not more than 115 mm.

4.7 Folding distance and number of folds

4.7.1 The folding distance of the filter element shall be uniform. The maximum folding distance of its unevenness, on the outer diameter of the filter element, shall not be greater than 1.5 times the nominal folding distance. The minimum folding distance shall not be less than 0.5 times the nominal folding distance.

4.7.2 Tolerance of number of folds of filter paper: For filter paper, which has a number of folds of less than 50, the tolerance is ±2 folds; for filter paper, which has a number of folds of 50 ~ 100, the tolerance is ±3 folds; for filter paper, which has a number of folds of more than 100, the tolerance is ±4 folds.

4.8 Dimensional tolerance, shape, position tolerance

4.8.1 The dimensional deviation of the inner hole diameter of the filter element's end cover shall meet the requirements of grade C in GB/T 1804-2000.

4.8.2 The height deviation of the filter element shall meet the requirements of grade C in GB/T 1804-2000.

4.8.4 The parallelism tolerance of both ends of the filter element shall not be greater than 1.5 mm. The measurement position shall be on the ring surface, which is 10 mm away from the inner diameter of the filter element.

4.8.3 The perpendicularity deviation, BETWEEN the center line of the filter element AND the end surface, shall meet the requirements of grade L in GB/T 1184-1996.

4.9 Appearance

4.9.1 The filter element shall be clean. The inner and outer surface shall be free of dirt and impurities.

Calculate and determine the increase in the mass of the absolute filter.

SDP - Specific dust penetration, in grams per cubic meter per minute [g/ (m3 · min-1)]

D - The increase in the mass of the absolute filter (that is, the mass of dust that passes through), in grams (g); qve - The rated air volume flow, in cubic meters per minute (m3/min).

5.5 Flame-retardancy

Carry out the test according to the method specified in GB/T 14656.

5.6 Folding distance and number of folds

The folding distance is measured by a vernier caliper. The number of folds is manually counted.

5.7 Dimensional tolerance, shape, position tolerance

The dimensional tolerances are measured by general measuring tools. The shape and position tolerances are measured in accordance with GB/T 1958.

5.8 Appearance

The appearance quality is inspected visually.

6.1 General

Each product can only exit-factory, after passing the inspection by the quality inspection department AND be accompanied by a product certificate.