A seal is a device or material that helps join systems, mechanisms, or materials together to contain pressure, prevent leakage of fluid (e.g. in a pumping system), or exclude contamination. The effectiveness of a seal depends on compression in the case of gaskets and adhesion in the case of sealants. Seals are installed in pumps in a wide range of industries including chemicals, water supply, paper production, food processing, and many other applications.[1]
A stationary seal may also be referred to as a "packing".
Seal types:
Seals relying on compression
- Closure (container)
- Crown cork, a.k.a. bottle cap
- Lid
- Compression fitting
- Compression seal fitting
- Diaphragm seal
- Double seam, the crimped seal used in canning
- End-face mechanical seal
- Face seal
- Gasket or mechanical packing
- Hose coupling
- Inflatable seal, a seal that inflates and deflates in three basic directions of operation: the axial direction, the radial-in direction, and the radial-out direction. Each of these inflation directions has its own set of performance parameters for measurements such as the height of inflation and the center-line bend radius that the seal can negotiate. Inflatable seals can be used for numerous applications with difficult sealing issues.
- Obturating ring
- Piston ring
- Radial shaft seal
- Spring-energized seal, a PTFE or polymer jacket energized by a metal spring that maintains the sealing load as the seal wears; used for extreme temperatures, aggressive media, and pressures from vacuum to very high where elastomeric seals fail.[2][3]
- Stopper (plug), a.k.a. bung or cork
- Washer
- Bodok seal, a specialized gas sealing washer for medical applications
- Bonded seal, also known as Dowty seal or Dowty washer. A type of washer with integral gasket, widely used to provide a seal at the entry point of a screw or bolt [4][5]
- O-ring
- O-ring boss seal
- Stuffing box (mechanical packing)
- Wiper seal
- Split seal,[6] multi-part seals that offer easier installation and maintenance
- Bridgman seal, a piston sealing mechanism that creates a high-pressure reservoir from a lower pressure source
Seals relying on fusion or adhesive bonding
- Glass-ceramic-to-metal seals
- Glass-to-metal seal
- Heat seal
- Hermetic seal
- Induction sealing or cap sealing
- Putty
- Sealant or adhesive
- Soldering and brazing
- Welding
Seals made by liquids blocking gases
- Ferrofluidic seal
- Trap (plumbing) or siphon trap
Non-contact seals
- Dry gas seal
- Hydrodynamic seal
- Hydrostatic seal
- Labyrinth seal, a seal which creates a tortuous path for the escaping gas or liquid
See also
References
- "GFS Mechanical Seals". Gallagher Seals. Retrieved 5 August 2021.
- "Spring Energized Seal". Omniseal Solutions, Spring Energized Seals. June 16, 2026. Retrieved June 16, 2026.
- "Polymers Spring-Energized Seal Handbook" (PDF). Omniseal Solutions, Polymers Spring-Energized Seal Handbook.
- "The Dowty Bonded Seal" (PDF). Archived from the original (PDF) on 22 February 2016. Retrieved 12 August 2016.
- "Bonded Seals". Retrieved 12 August 2016.
- "Information about Split Seals". Mechanical Seals. Retrieved 2023-06-02.