3.1.1 Water cooling
Connection to an external cooling water supply dissipates heat which is generated during compression
of the gas. The cooling water flows through the cooling chambers of the screw pump and absorbs the
heat there.
3.1.2 Temperature monitoring
The switching temperatures are dependent upon the pump size and the type of cooling system. Tem-
perature monitoring prevents overheating and potential blockages in the screw pump.
3.1.3 Gas ballast
An integrated gas ballast system serves the controlled supply of ambient air or inert gas into the suction
chamber. Gas ballast supports the reduction of condensate accumulating in the pumping system.
3.1.4 Sealing gas system
Sealing gas is used to protect the screw pump in dusty processes, or wherever excessive gas through-
puts are prevalent. Sealing gas prevents the ingress of damaging substances into the motor and bear-
ing area. The supply is carried out either via a sealing gas valve or a sealing gas throttle without control.
3.1.5 Silencer
The silencer reduces the noise level during operation without exhaust line.
3.2 Identifying the product
► To ensure clear identification of the product when communicating with Pfeiffer Vacuum, always
keep all of the information on the rating plate to hand.
► Observe the motor-specific data on the motor rating plate attached separately.
3.3 Product features
Pump type
Characteristics
Hepta 450 L
● Nominal pumping speed at 50 Hz: 350 m
3
/h
● Nominal pumping speed at 60 Hz: 420 m
3
/h
● Water cooling
● Temperature switch
Hepta 650 L
● Nominal pumping speed at 50 Hz: 650 m
3
/h
● Nominal pumping speed at 60 Hz: 650 m
3
/h
● Water cooling
● Temperature switch
Tbl. 4:
Characteristics of the screw pumps
3.4 Scope of delivery
● Screw pump
● Lubricant
● Locking caps for vacuum and exhaust connection
● Operating instructions
Product description
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