Mechanical Seals from Burgmann
Mechanical seals are used for the sealing of rotating shafts against a stationary housing, e.g. in pumps and agitators. The stationary part of the seal is usually located at the housing, the rotating part is fixed on the shaft. The high-precision face-machined sliding faces rotate axially in opposition. The sliding faces are pressed against each other by means of spring force, thus preventing the opening of the seal at stand-still. The seal faces are statically sealed against the housing and the shaft by secondary seals (O-rings). With the entry of the pumped medium into the minimal sealing gap a lubricating film is generated and the sealing effect is thus obtained.
The design, arrangement and combination of materials of the seal is basically determined by pressure, temperature, speed of rotation and quality of the pumped medium. Shaft diameters of 5...500 mm, pressures from 10 torr ....250 bar, temperatures from -200°C... +450°C and sliding velocities up to 150 m/s limit the operating range of mechanical seals. Additional seal supply systems or buffer fluid systems may be required, dependent on the mode of operation, the quality of the medium and the seal arrangement..