The EH mechanical booster pump, based on the simple Roots principle, remains the favourite pump for applications where high pumping speeds are required for pressures in the region of 0.01 to 10 mbar. This pump must always be backed by another pump, which can deliver against a high-pressure differential to atmospheric pressure.

Operating at relatively low pressures, the mechanical booster pump is not exposed to the same concentrations of corrosive process media as is the backing pump, which makes it highly reliable.

The EH2600FX pump is supplied for use with PFPE oil. This enables them to be used in harsh (corrosive) processes, or where the presence of Oxygen will result in rapid degradation of hydrocarbon oils. Fomblin® must be purchased separately for PFPE prepared pumps.

Edwards recommends that the EH2600FX pump should NOT run continuously on pressures >10 mbar.

Features and Benefits

  • Suitable for applications where high pumping speeds over 3000 m3h-1/1776 ft3min-1 are required in the pressure region of 0.01 to 50 mbar/0.0075 to 37.5 Torr.
  • Operating at relatively low pressures makes it highly reliable.
  • The EH pumps have a high quality, oil-free pumping mechanism. This offers:
    • Quiet, vibration free operation.
    • ­Rugged and corrosion resistant.
    • ­Advanced shaft-seal technology with no oil contamination of the process chamber
  • The corrosion resistant pumping mechanism is manufactured from high grade cast iron.
  • The proven shaft-seal arrangement ensures that no oil enters the pumping stator, and the absence of internal and external by-pass lines and valves which may corrode or stick minimizes maintenance requirements.
  • The design of the shaft seals is optimized to ensure that no lubricants can migrate into the pumping mechanism. This maintains booster pump performance in applications which demand the highest standard of cleanliness. In addition, this prevents the build-up of trapped particles on the rotor lobes and end-faces which have very close tolerances.
  • The dynamically balanced rotors and precision ground gears contribute to the smooth, quiet operation of the pumps, as demanded by manufacturers of advanced technology equipment.


  • Semiconductor processing
  • Vacuum distillation
  • Vacuum packaging
  • Steel de-gassing
  • Thin film coating
  • Vacuum metallurgy
  • Low density wind tunnels
  • Space simulation
  • Vacuum impregnation
  • Oil drying and de-gassing
  • Pharmaceutical freeze drying
  • CO2 lasers
Technical data  
Displacement (swept volume)  
  50Hz 2590 m3h-1 / 1525 ft3min-1
  60Hz 3110 m3h-1 / 1830 ft3min-1
Effective pumping speed with backing pump  
  E2M175 1750 m3h-1 / 1031 ft3min-1
  E2M275 1900 m3h-1 / 1119 ft3min-1
Pressure differential across pump  
  50Hz 0-120 mbar / 0-90 Torr
  60Hz 0-67 mbar / 0-50 Torr
Inlet connection ISO160
Outlet connection ISO100
Rotational speed  
  50Hz 0-2900 rpm
   60Hz 0-3500 rpm
Operating continuous inlet pressure 0-1000 mbar / 0-760 Torr
Maximum outlet pressure 1000 mbar / 760 Torr
Recommended backing pumps GXS250, GXS450, E2M175, E2M275
Electrical supply  
  50Hz 220-240V / 380-415V
  60Hz 208-230V / 460V
Motor power  
  Hydrocarbon 11kW / 15hp
  PFPE 11kW / 15hp
  ATEX 11kW
  Explosion proof 15hp
Ambient temperature range  
  Operating 5 to 40°C / 40 to 104°F
  Storage -10 to 80°C / 14 to 176°F
Maximum operating humidity 90% RH
Recommended cooling water supply pressure 2-6 bar
Cooling water connections 3/8 inch BSP male
Recommended oil  
  Standard version Ultragrade 20
  PFPE version Fomblin® YVAC 16/6
Oil capacity  
  Gear case 3.5 litre
  Coupling cover 6.5 litre
  Shaft seal reservoir 1.5 litre
Weight 345 kg