The filtration efficiency of the hepa filter itself is generally tested by the manufacturer, and the filter filtration efficiency report sheet and certificate of compliance are attached when leaving the factory. For enterprises, hepa filter leak testing refers to on-site leak testing after the installation of hepa filters and their systems. It mainly checks for small pinholes and other damage in filter material, such as frame seals, gasket seals, and filter leaks in structure, etc.
The purpose of leak testing is to promptly discover defects in hepa filter itself and its installation by checking the sealing of the hepa filter and its connection with installation frame, and take corresponding remedial measures to ensure the cleanliness of the clean room.
The purpose of hepa filter leak testing
1. The material of the hepa filter is not damaged;
2. Proper installation.
How to do leak testing in hepa filter
HEPA filter leak testing basically involves placing challenge particles upstream of the hepa filter, and then using particle counter on the surface and frame of the hepa filter to search for leaks. There are several different methods of leak testing, suitable for different situations.
Testing method
1. Aerosol photometer testing method
2. Particle counter testing method
3. Full efficiency testing method
4. External air testing method
Testing instrument
The instruments used are aerosol photometer and particle generator. The aerosol photometer has two display versions: analog and digital, which must be calibrated once a year. There are two types of particle generators, one is an ordinary particle generator, which only requires high-pressure air, and the other is a heated particle generator, which requires high-pressure air and power. The particle generator does not require calibration.
Precautions
1. Any continuity reading exceeding 0.01% is considered a leak. Each hepa filter must not leak after testing and replacement, and the frame must not leak.
2. The repair area of each hepa filter shall not be greater than 3% of the area of the hepa filter.
3. The length of any repair shall not exceed 38mm.
Post time: Feb-05-2024