This requires one seal face to remain stationary while the other rotates. Typically a drive pin, tab, clip or screw is used to hold the seal face in position and to drive the rotating housing and seal face. To Keep the Seal Faces Contacting Mechanical seals are designed to prevent visible leakage from the seal faces. Designers specify a spring mechanism to provide adequate, but not excessive force to the seal faces. Typical spring mechanisms include single coil spring, multiple coil spring, wave spring and metal bellows.
Springs typically become damaged or cracked when exposed to excessive axial motion.
Improper spring material selection can lead to premature cracking. Locating the spring mechanism away from product to prevent clogging leads to enhanced reliability. Metal components are also vulnerable to damage. Examples are shown in Photos 15-17. The parts in Photo 15 have been scored, either by the rotating or stationary components.