Industrial Pump Seals

This is a general term that is applied to mechanical seals that employ an O-ring or other elastomer or plastic seal as the floating secondary seal. They can vary from simple unbalanced designs that would be used in applications comparable to those discussed for elastomer bellows seals, section 3,4.4.2, up to very specialist high pressure, high duty seals. A general purpose unbalanced pusher seal is shown in Figure 3.90, with hydraulically balanced designs discussed in more detail below. The term pusher derived from the fact that the spring force pushes the seal along the shaft or sleeve to provide the sealing contact. The most common type of secondary seal for the floating component is an elastomer 0-ring.