1 Supplementary Operating Manual
6 of 12
Double Mechanical Seals
NOTE
To reduce friction forces when assembling the seal, wet the shaft sleeve and the
location of the stationary ring with water.
CAUTION
Elastomers in contact with oil/grease
Shaft seal failure!
▷
Use water as assembly lubricant.
▷
Never use oil or grease as assembly lubricant.
2.
Fit the rotating assembly of mechanical seals 433.01 and 433.02 on shaft sleeve
523 (observe distance A).
3.
Carefully position the stationary assembly (mating ring) of mechanical seal
433.01 with the O-ring in casing cover 161. Make sure to apply pressure evenly.
4.
Insert the ring and circlip 932.05 in casing cover 161.
5.
Carefully position the stationary assembly (mating ring) of mechanical seal
433.02 with the O-ring in seal cover 471. Make sure to apply pressure evenly.
6.
Position gasket 400.15 (for SU 25: joint ring 411.15) in seal cover 471.
7.
Slide seal cover 471 onto shaft 210 until it rests against bearing bracket 330 or
the motor.
8.
Slide shaft sleeve 523 (with the rotating assemblies) with new gasket 400.75
onto shaft 210.
9.
On models with a bolted casing cover:
Screw back but do not remove forcing
screws 901.31. Slide casing cover 161 onto bearing bracket 330 or drive lantern
341, as applicable. While doing so, carefully slide seal cover 471 onto casing
cover 161.
On models with a clamped casing cover:
Slide casing cover 161 onto bearing
bracket 330 or drive lantern 341, as applicable. While doing so, carefully slide
seal cover 471 into casing cover 161. Insert bolts 901.98 (long-coupled design) or
screws 914.22 (close-coupled design) and tighten to fasten casing cover 161 in
place.
10.
Fit and tighten hexagon nuts 920.15 at casing cover 161.
11.
Fit and tighten nuts 920.02 at seal cover 471.
12.
Slide spacer sleeve 525 (shaft unit 35 only) onto shaft 210.
13.
Place key 940.01 in the shaft keyway.
14.
Slide discs 550.02/.04, impeller 230, disc 550.95 (shaft unit 25 only) and safety
device 930.95 onto the shaft. Tighten with hexagon nut 920.95.
15.
Position fittings 720.13/.14 with joint rings 411.13/.14 in seal cover 471 or casing
cover 161, as applicable, and tighten.
16.
Carry out all other relevant steps given in operating manual 2753.81 or 2753.82.
1.5 Seal supply system
1.5.1 Applications
In order to function properly, the mechanical seals require a barrier fluid. The barrier
fluid completely fills the space between the inboard and the outboard mechanical
seal. It serves two purposes:
▪
Dissipate friction heat
▪
Prevent the fluid handled from entering the sealing gap
