Pulsafeeder Pulsalube 8 GS Ultra, Operation & Maintenance Manual

Page: 111 / 198

Blatt / sheet
Dokument / document
Ausgabe / issue
ZU.016.02e
B / 10.07.08
1 (2)
Mechanical seal, double acting/back-to-back
1 Area of application
Conveying liquids with the following properties
 aggressive, toxic
 sticky, highly viscous
 polymerising
 tendency to leave deposits
 high vapour pressure or gaseous
 high pressure, high temperature
2 Buffer fluid
2.1 General
The buffer fluid fills the space between the set of mechanical seals on the medium
side and the atmosperic side
2.2 Task
 to dissipate the corresponding frictional heat.
 to avoid infiltration of the product into the sealing gap.
2.3 Medium
 clean, cold and stable liquid is used, e.g. water.
 it must be compatible with the product and free of solids.
 it must not have a tendency to leave deposits.
 it should have low viscosity and a good thermal conductivity.
 Bear in mind the resistance to corrosion of all acontact parts.
2.4 Pressure
The buffer fluid pressure must always be 1,5-2 bar greater than the maximum product
pressure. This ensures that infiltration of the product in the mechanical seal (GLRD)
sealing gap is prevented.
medium side atmospheric side
double acting back-to-back