2.5.3 Portfolio overview
HeptaDry pumps are dry screw pumps for applications in the low and medium vacuum ranges where high volume flow rates are required. The pumping speeds of this product line range from 100 to 600 m3/ h. Ultimate pressures of under 0.1 mbar are attained.


Figure 2.10:
HeptaDry™ operating range
Regardless of the model in question, HeptaDry pumps can be continuously operated in the operating range shown in Figure 2.10. Their effective pumping speed declines in the p < 1 mbar pressure range due to the ever-stronger backflow between the individual sealed volumes within the pump. See also Formula 2-5. There is a similar reason for the decrease in pumping speed toward high pressure, as in this case the gas is compressed to pressures in excess of atmospheric pressure through internal compression, and consequently backflow increases significantly due to the high differential pressure.
The standard equipment that comes with the pumps includes: Inlet sieve, water-flow cooling with thermostatic valve and thermometer, silencer with non-return valve and frame-mounted design with vibration dampers.
The pumps are driven by a three-phase, temperature-monitored asynchronous motor that is suitable for 50 and 60 Hz (3,000 or 3,600 rpm). Coupling, bearings and flanges are standard components.

Figure 2.11:
HeptaDry™ with connections and accessories


Table 2.10:
HeptaDry™ series connections


Table 2.11:
HeptaDry™ performance data
The HeptaDry line is rounded out by the RevoDry 50. The RevoDry 50 is available either as an S version or a P version with a variety of accessories. It, too, is a dry pump with a pumping speed of 50 m3 h.
Please note the following in connection with pumps that are supplied in the standard scope of delivery:
- They are not suitable for pumping toxic, flammable and/or explosive gases
- They are not suitable for corrosive gases
- No foreign matter
- No deposit-forming media
- Limited entrainment of fluid (surge fluid)
- Permissible inlet temperature between 70 and 200 °C as a function of inlet pressure
- Coolant limits must be observed: Temperature 10 – 25 °C, pressure 3 – 6 bar
- Not gas tight
Contact
Address
Headquarters postal address
Pfeiffer Vacuum GmbH
Berliner Strasse 43
35614 Asslar
Germany
P.O. Box
Pfeiffer Vacuum GmbH
Berliner Strasse 43
35614 Asslar
Germany
T +49 6441 802-0
F +49 6441 802-1202