O-ring face seal fitting
Trelleborg Sealing Solutions

There are two different types of Mechanical Face Seals / Heavy Duty Seals:

Type DO is the most common form that uses an O-Ring as a secondary sealing element
Type DF has an elastomer with a diamond-shaped cross section as a secondary sealing element instead of the O-Ring

Both types consist of two identical metal seal rings mounted in two separate housings face-to-face on a lapped seal face. The metal rings are centered within their housings by an elastomer element. One half of the Mechanical Face Seal remains static in the housing, while the other half rotates with its counter face.

Applications

Mechanical Face Seals are predominantly used for sealing the bearings in construction machinery or production plants operating under extremely arduous conditions and subject to severe wear.

These include:

Tracked vehicles, such as excavators and bulldozers
Conveyor systems
Heavy trucks
Axles
Tunnel boring machines
Agriculture machines
Mining machines