The installation and maintenance of high-efficiency filters with separators should focus on two core aspects: sealing performance and filtration efficiency. Any improper operation may directly lead to excessive particles in the clean area.

These two links are the key to ensuring the long-term effective operation of the filter. Installation determines the initial effect, while maintenance determines the long-term stability. The following lists the core precautions, respectively, from the aspects of installation and maintenance.
I. Installation Precautions: Prevent initial leakage
The core objective of the installation is to ensure that there are no leakage points between the filter and the installation frame or within the filter itself.
Preparations before installation: Before installation, it is necessary to check whether the primary and medium-efficiency filters in the clean room have been replaced, and whether there is no dust or debris in the ventilation ducts to avoid subsequent contamination of the HEPA. At the same time, it is necessary to check whether the packaging of the HEPA is intact, whether the filter paper is damaged or deformed, and whether the sealing glue on the frame is uniform.
Sealing treatment: Special sealing materials (such as polyurethane foam glue, sealing gaskets, and liquid tank glue) must be used to fill the gap between the filter and the installation frame. When installing, apply force evenly to ensure that the sealing material is fully adhered without any bubbles or gaps. This is the key to preventing the bypass of unfiltered air.
Installation sequence and force: During installation, the fixing bolts should be tightened in a diagonal order to prevent deformation of the filter frame due to uneven local force and damage to the sealing performance. The bolt force should be moderate. Excessive force may damage the filter paper, while too loose a force cannot ensure a seal.
Post-installation inspection: After installation is completed, a leak test must be conducted (usually using an aerosol photometer), with a focus on inspecting the filter frame, sealing surface, and filter paper itself. Only after confirming there is no leakage can it be put into use.
Ii. Maintenance Precautions: Ensure long-term efficiency
The core of maintenance lies in regular monitoring and timely replacement to prevent the filter from being clogged or failing, which could affect the cleanliness.
Regular differential pressure monitoring: Install differential pressure gauges at the inlet and outlet of the filter and record the changes in differential pressure regularly. When the pressure difference exceeds 1.5 to 2 times the initial pressure difference, it indicates that the filter is severely clogged and needs to be replaced immediately. If the pressure difference drops suddenly, it may indicate that the filter paper is damaged or the seal has failed, and an emergency leak detection is required.
Replacement cycle control: Even if the pressure difference does not exceed the standard, a fixed replacement cycle (usually 1-3 years) should be set according to the usage environment and the manufacturer’s recommendations to avoid a decrease in filtration efficiency due to the aging of filter paper. Before replacement, the air supply system of the corresponding area should be turned off, and the replacement area should be cleaned to prevent the introduction of contaminants during the operation.
Replacement operation specifications: When replacing, clean gloves and dust-free suits must be worn to avoid direct contact of hands with the filter paper. The removed old filters need to be sealed and packaged before being moved out of the clean area to prevent the spread of the contaminants they retain. After the new filter is installed, a leak detection test needs to be repeated. Only after passing the test can the system be restarted.
Daily environmental coordination: Keeping the floor and walls of the clean room clean can reduce the generation of indoor particles, which can lower the load on HEPA and extend its service life. At the same time, ensure that the primary and medium efficiency filters are replaced as per regulations to prevent large particle contaminants from clogging the HEPA prematurely, which could lead to its premature failure.