Commissioning, Startup, Operation, and Shutdown
Model 3410 Installation, Operation, and Maintenance Manual
42
Single inside unbalanced or integrally balanced seals
The following figure illustrates a single inside unbalanced or integrally balanced (metal bellows)
seal for an S group pump. This design incorporates the standard 420SS sleeveless shaft and
oversized stuffing box bore. The stuffing box bore is used to pilot the standard gland.
1. Sleeveless 420SS shaft
2. Oversize stuffing box bore
3. ID pilot fit in stuffing box
4. Standard two-bolt flush gland (cast iron or bronze)
5. O-ring mounted stationary seat
Figure 27: Single inside unbalanced or integrally balanced seal for an S group pump
The following figure illustrates the same type of seal for M group pumps. Note that the shaft is
protected by sleeves and sleeve nuts as standard. All other features and details are the same.
1. Standard shaft sleeve
2. Oversize stuffing box bore
3. ID pilot fit in stuffing box
4. Standard two-bolt flush gland (cast iron or bronze)
5. O-ring mounted stationary seat
Figure 28: Single inside unbalanced or integrally balanced seal for an M group pump
Conventional balanced seals
Conventional balanced seals require a stepped shaft sleeve. The following figure shows an S
group pump with a stub sleeve to accomplish the seal balancing.