1. How Does Gasket Seal Achieve Sealing?
Gasket Seal uses an elastic gasket installed on the frame of the HEPA filter. A clamping device compresses the gasket tightly against the mounting frame.
Typical structure:
Filter Frame → Gasket → Mounting Surface → Clamping Pressure
Common materials include neoprene, EPDM, polyurethane foam, and closed-cell foam. It has a simple structure, relatively low cost, and is easy to install and replace. It is suitable for conventional HEPA terminal housings, AHUs, and general clean air systems.
During installation, the frame must be flat, and the clamping pressure must be uniform. If the gasket is aged, the joints are not properly sealed, or the corners are not fully compressed, bypass leakage may occur.
2. How Does Gel Seal Achieve Sealing?
Gel Seal usually uses a gel-filled channel on the filter frame. During installation, the Knife Edge of the terminal housing or filter housing is inserted into the gel channel to form a continuous seal.
Typical structure:
Housing Knife Edge → Gel Channel → Filter Frame → Airtight Seal
The gel surrounds the knife edge and compensates for minor dimensional deviations and uneven surfaces. It generally provides better seal continuity and a lower risk of bypass leakage, making it suitable for strict leak testing and high-cleanliness environments.
Gel Seal must be used with a knife-edge mounting structure, and its purchase cost is usually higher. During transportation, installation, and replacement, the gel should be protected from contamination, overflow, cracking, or repeated damage by the knife edge.
3. Key Comparison Between Gasket Seal and Gel Seal
| Comparison Item | Gasket Seal | Gel Seal |
|---|---|---|
| Sealing Principle | Compression of an elastic gasket | Knife edge inserted into a gel channel |
| Mounting Structure | Flat clamping frame | Knife Edge structure |
| Seal Continuity | Depends on uniform compression | Usually better |
| Compensation for Installation Deviations | Relatively limited | Relatively strong |
| Replacement Convenience | More convenient | Gel and knife edge must be protected |
| Initial Cost | Usually lower | Usually higher |
| Typical Applications | AHUs and general cleanrooms | Pharmaceutical facilities, hospitals, and laboratories |
It should be noted that Gel Seal does not mean higher filtration efficiency. H13 and H14 indicate the filtration performance of the filter element, while Gasket Seal and Gel Seal address sealing between the filter frame and the housing.
4. How to Select for Different Projects?
Conventional AHUs and Commercial Clean Air Systems: If the mounting frame is flat, the clamping device is reliable, and leakage control requirements are not particularly strict, the lower-cost and easier-to-maintain Gasket Seal can be selected first.
Pharmaceutical and Aseptic Production Environments: Filling areas, aseptic production lines, and high-grade clean areas usually require strict integrity testing. Gel Seal is more suitable for use with gel-seal HEPA terminal housings.
Hospitals and Biosafety Laboratories: The sealing method should be selected according to the risk level, supply and exhaust air direction, and leak testing requirements. High-risk exhaust systems should also consider bag-in/bag-out structures and safe replacement methods.
Semiconductor and FFU Systems: The sealing structure should be selected according to the FFU housing interface, installation method, maintenance frequency, and overall leakage control requirements.
5. What Parameters Should Be Confirmed During Procurement?
The following information should be provided before procurement:
H13 or H14 filtration grade;
Rated airflow and initial pressure drop;
External dimensions and installation direction;
Terminal housing or filter housing interface structure;
Gasket mounting surface or gel channel position;
Gasket material, thickness, and joint configuration;
Gel channel dimensions, gel type, and knife-edge specifications;
Operating temperature, humidity, and chemical environment;
PAO/DOP scan leak testing requirements.
If the original equipment uses a knife-edge structure, the replacement filter must match the corresponding gel channel and knife-edge dimensions. If a gasket compression structure is used, the gasket position, compression ratio, and clamping method should be verified.
6. Frequently Asked Procurement Questions
Is Gel Seal always better than Gasket Seal?
Not necessarily. Gel Seal is suitable for environments with strict sealing requirements, but a correctly installed Gasket Seal can also meet the requirements of conventional AHUs and general clean air systems.
Can the gasket be reused?
When replacing the filter, check whether the gasket is aged, damaged, or permanently deformed. It should be replaced if reliable sealing cannot be guaranteed.
Is leak testing still required after gel sealing?
Yes. A reliable sealing structure does not guarantee that no leakage exists after installation. Critical projects should still perform scan leak testing on both the filter media and the frame.
7. Jiangsu Yueboyang HEPA Sealing Solutions
Jiangsu Yueboyang provides separator HEPA filters, mini-pleat HEPA filters, and H13/H14 terminal filters with Gasket Seal and Gel Seal structures. Products can be matched according to the housing interface, rated airflow, cleanliness level, and leak testing requirements.
Gasket Seal can be evaluated first for conventional AHUs and cost-sensitive projects. Gel Seal can be considered for pharmaceutical facilities, hospitals, biosafety laboratories, and high-grade clean areas. Proper selection should meet all of the following requirements:
Filter Efficiency + Frame Compatibility + Airtight Seal + Integrity Test
Only when filtration efficiency, interface dimensions, sealing structure, and on-site leak testing are all qualified can the HEPA system achieve stable and reliable air filtration.
