Mechanical Seals are quite complicated assemblies when compared to a Gland Packing arrangement. There are many different types of Mechanical Seals for different applications. Illustrated below is a General Assembly Drawing of a typical Single Bellows Type Mechanical Seal.
from Pump Discharge
Mechanical Seals can generally be split into two basic sub-assemblies:
• The Rotating Assembly.
The rotating assembly within the Mechanical Seal is fitted and attached to the Pump or Compressor Shaft.
As the Pump or Compressor Shaft spins, the Mechanical Seal Rotating Assembly rotates within the Mechanical Seal.
• The Stationary Assembly.
The stationary assembly within the Mechanical Seal is fitted and attached to the Pump or Compressor casing. This part of the Mechanical Seal remains stationary and does not rotate with the Pump or Compressor rotor.
A half section of the same Single Bellows Mechanical Seal as detailed previously in this Module can be viewed in the diagram below. The two Mechanical Seal sub-assemblies; the rotating assembly and the Stationary assembly are Clearly detailed in the following illustration.