Seal (mechanical)

Compression seal example

A mechanical seal is a device that helps join systems or mechanisms together by preventing leakage (e.g. in a plumbing system), containing pressure, or excluding contamination. The effectiveness of a seal is dependent on adhesion in the case of sealants and compression in the case of gaskets.

A stationary seal may also be referred to as 'packing'.

Seal types:

• Induction sealing or cap sealing
• Adhesive, sealant
• 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
• Bridgman seal, a piston sealing mechanism that creates a high pressure reservoir from a lower pressure source
• Bung
• Compression seal fitting
• Diaphragm seal
• Ferrofluidic seal
• Gasket or Mechanical packing
  • Flange gasket
  • O-ring
  • O-ring boss seal
  • Piston ring
• Glass-to-metal seal
• Glass-ceramic-to-metal seals
• Heat seal
• Hose coupling, various types of hose couplings
• Hermetic seal
• Hydrostatic seal
• Hydrodynamic seal
• Inflatable seal Seals that inflate and deflate in three basic directions of operation: the axial direction, the radial-in direction, and the radial-out direction. Each of these inflation directions has their 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.
• Labyrinth seal A seal which creates a tortuous path for the liquid to flow through
• Lid (container)
• Rotating face mechanical seal
• Face seal
• Plug
• Radial shaft seal
• Trap (plumbing) (siphon trap)
• Stuffing box (mechanical packing)
• Wiper seal
• Dry gas seal

See also

• Leakage (chemistry)