KSM 200 Oil Diffusion Ejector Pump


The KSM-200 is a three stage, non-fractionating diffusion-ejector pump.

Three umbrella type vapor stages, positioned in the vertical column, have nozzles through which jets of vapor are emitted to entrain the gas entering the pump inlet. The compressed gas is then passed on to the ejector stage in the forearm of the pump.

The pump achieves peak operating pumping speed of 300 liters/second over a range from 10-2 to 10-4 Torr and has an ultimate pressure in the 10-5 Torr range. The pump has a forepressure tolerance of .6 Torr.

The pump comes equipped with standard water-cooling lines with disconnect fittings. Quench lines in the boiler provide rapid cooling of oil when systems operation is stopped.

Pump has four (4) 500-watt cartridge immersion heaters which insert into wells for simplified maintenance.


  • High Throughput over wide range: 300 liters / second from 10-2 to 10-4 Torr range.
  • Efficient Heat Transfer
  • Replaceable heaters
  • Foreline Ejector stage allows operation at higher pressures (up to .1 Torr)
  • Fast Pump Down Times
  • Cooling and quench coilspumpdrawing


The KSM-200 is a three stage, high vacuum (10-3 to 10-4 Torr range) vapor pump designed for heavy gas load applications such as in vacuum distillation, evaporation, vacuum arc melting, freeze drying, impregnation and casting of metals. The pump has no moving parts which may be corroded by the acidic nature of the material being pumped. These pumps are used in place of mechanical roots type blower.



Inlet connection: Flange
– O.D.: 9″
Bolt circle: 7-1/2″
No. of holes: 8
– Hole diameter: 4″

Outlet connection: 
O.D.: 4-5/8″
Bolt circle: 3-1/2″
No. of holes: 4
Net weight: 38 lbs
Shipping weight: 51 lbs.
Platesu speed (liters per second): 300
Typical air throughput in pumpdown range (Torr-liters per second): 3.2

All data obtained with Convoil-20 pump fluid. Pump equipped with cooling coil thermostat switch. Pumping speed measured with Convoil 20 diffusion pump.

Ordering Information

KSM-200: Diffusion ejector pump stn. stl. csg., water-cooled 2KW, 115V, 4 cartridge heater
Part Number: 500089

Replacement heaters for KSM-200, 115V, 500W
Part Number: 51832

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