The EXT556H incorporates our hybrid bearing and enhanced molecular drag pumping technologies with turbopump stages on a single rotor. It is an 80V pump and therefore must be used with an EXC300 controller.

Features and Benefits

  • High critical backing pressure
  • High volume flow rate - fast pump down
  • Multistage Holweck molecular drag mechanism gives high compression ration for light gases
  • Ultimate vacuum <10-10 mbar
  • Proven EXT performance and reliability
  • Hybrid bearing configuration
  • Maintenance free – oil bearing reservoir sealed for life
  • Machined monobloc rotor
  • DC motor drive
Technical data  
Main Inlet flange DN160ISO-K/DN160CF
Outlet Flange DN25NW
Vent/purge port 1/8 inch BSP
Inlet pumping speed* (compression ratio)  
  N2 540 ls-1 (>1010)
  He 580 ls-1 (108)
  H2 500 ls-1 (106)
  Ar 510 ls-1 (>1010)
Ultimate Pressure (CF variant) <10-10 mbar
Recommended backing pump RV12/nXDS10i
Max continuous inlet pressure (N2, He, H2)**  
  forced air cooled, 30 °C ambient 1 x 10-3 mbar
  forced air cooled, 35 °C ambient 5 x 10-4 mbar
  water cooling at 15 °C 2 x 10-3 mbar
Nominal rotational speed 50000 rpm
Start time to 90% speed  
  EXC300 6.5 min
Cooling method Forced air/water
Ambient air temp for forced air cooling 0 °C - 35 °C
Recommended cooling water flow rate
(water at 15°C)
15 lh-1
Water temp range 10 - 20 °C
Max inlet flange temp 80 °C
Operating attitude Vertical and upright,
through to horizontal
Noise level at 1 metre  
Max axial magnetic field  
Max radial magnetic field  
Recommended controller EXC300
Quiescent power consumption 35 W
Electrical supply voltage  
Electrical supply frequency (EXC250/300) 47 – 63 Hz
Max power output for pump  
EXC300 290W
EXT556H ISO/CF 13.4/21.2 kg
EXT556HF ISO/CF 19.3/20.5 kg
EXC300 4.6 kg

* Measured without inlet screen. Inlet screens are supplied fitted and may reduce speed by up to 20%
** With backing pressure