Metal Bellows Seals
Metal bellows seals have many advantages over common pusher seals. The obvious advantages include:
- No dynamic o-ring eliminating the possiblity of hang-ups or shaft wear.
- Hydraulically balanced metal bellows allow the seal to handle more pressure without heat build up.
- Self Cleaning. Centrifugal force throws solids away from the seal face
- Trim design allow fit into tight seal boxes
- Even face loading
- No Springs to clog
Most often metal bellows seals are thought of as High Temperature seals. But metal bellows seals are often effective in a wide range of other seal applications. The most common of these is chemical, general water pump applications. For many years an inexpensive form of metal bellows seals have been used very successfully in the waste water / sewage industry and in the agricultural fields pumping irrigation water. These seals were generally made of a formed bellows rather than a welded bellows. Welded bellows seals are much stronger and have superior flex and recovery characteristics which are more ideal to holding seal faces together but cost more to manufacture. Welded metal bellows seals are less prone to metal fatigue .
Because metal bellows seals only require one o-ring, and because that o-ring can be made with PTFE, metal bellows seals are and excellent solution on chemical applications where Kalrez, Chemrez,Viton, FKM, Buna, Aflas or EPDM are not compatible. Unlike an ASP Type 9 seal the o-ring will not cause wear because it is not dynamic. Installation with a PTFE o-ring must be done with more attention paid to surface of the shaft condition, however PTFE encapsolated o-rings are also available in most sizes to aid in sealing irregular surfacing..
American Seal & Packing has negotiated the production of welded metal bellows seals made for us at a cost similar to formed bellows. As a result we can offer welded metal seals that will last longer in the field resulting in less pump down time, less loss production and fewer labor costs, saving you incalculably.
Of course none of this would be attainable if the quality system was not insuring consistent, repeatable, quality. Manufactured under an ISO-90001 system, maintaining the quality of the materials, and workmanship. On receipt of the product the metal bellows seals are re-inspected, labeled and packaged.
At some point any seal will wear. American Seal & Packing also does seal repairs. To assure you always get your seal back regardless of who does your seal repair, we recommend having your new seals laser etched when you order them new. At the time of your order just indicate how you would like your metal bellows seal marked.