Munsch NPC Series - Auxiliary Operating Systems; Sealing Systems; Tab. 6 Quenching - Variants and Characteris; Tab. 7 Foreign Blocking - Variants and Characteristics

Layout and function
3.4 Auxiliary operating systems
3.4.1 Sealing systems
Only one of the following sealing systems can be used.
Quenching
1 2
3
Fig. 5 Double mechanical seal with quench
(operating principle)
1 Pumped medium
2 Sealing medium (unpressurized)
3 Double mechanical seal
With quenching, the pressure of the pumped medium exceeds
the pressure of the sealing medium. The sealing friction sur-
faces of the product-side seal are lubricated by the pumped
medium.
Application examples:
• pumped media that crystallize in air, causing long-term
damage to the seal
• prevention of odors
• seal cooling
Variant
Sealing medium
characteristics
Open system
• supplied and drained
continuously
• unpressurized
Closed system
• circulates in a closed
cycle
• unpressurized
Tab. 6 Quenching – variants and characteristics
Blocking
1 2
3
Fig. 6 Double mechanical seal with foreign blocking
(operating principle)
1 Pumped medium
2 Sealing medium (pressurized)
3 Double mechanical seal
With foreign blocking, the pressure of the se aling medium
exceeds the pressure of the pumped medium. The sealing
friction surfaces are lubricated by the sealing medium.
Application examples:
• pumped media that crystallize or carry solids, cau sing long-
term damage to the seal
• toxic pumped media
• pumped media presenting an environmental hazard
Variant
Sealing medium
characteristics
Open flow system
• supplied and drained
continuously
• pressurized
Closed flow system
• circulates in a closed
cycle
• pressurized
Tab. 7 Foreign blocking – vari ants and characteristics
12 NPC series BA-2005.07 EN – 02