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.
The EH250FX 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 EH250FX 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
|Displacement (swept volume)|
|50Hz||310 m3h-1 / 185 ft3min-1|
|60Hz||375 m3h-1 / 220 ft3min-1|
|Effective pumping speed with backing pump|
|E1M40 or E2M40||240 m3h-1 / 141 ft3min-1|
|E1M80 or E2M80||274 m3h-1 / 161 ft3min-1|
|Pressure differential across pump|
|50Hz||0-180 mbar / 0-140 Torr|
|60Hz||0-150 mbar / 0-115 Torr|
|Rotational speed ‡|
|Operating continuous inlet pressure||0-1000 mbar / 0-760 Torr|
|Maximum outlet pressure||1000 mbar / 760 Torr|
|Recommended backing pumps||GV80, E1M/E2M40, E1M/E2M80|
|Electrical supply voltage, 3-ph|
|50Hz||220 – 240V / 380 – 415V|
|60Hz||208-230V / 460V|
|Hydrocarbon||2.2 kW / 3 hp|
|PFPE||1.5 kW / 2 hp|
|Explosion proof||3 hp|
|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 oil||Ultragrade 20|
|Coupling cover||1.5 litre / 1.6 qt|
|Shaft seal reservoir||0.125 litre / 0.25 qt|
|Weight*||66 kg / 142 lb|
*Weight refers to IND version