Cryo Pumps

We specialize in Brooks Polycold and CTI CryoTorr, OnBoard cryo pumps and compressors. We rebuild them in house and guarantee the service with a one year warranty for all models except the older idiosyncratic ones. We make custom length lines and sell various accessories.

The cryogenic pump has recently become the most widely used of the high vacuum pumps. This is due to high pumping speed, dry operation and low maintenance requirements. The cryo pump works by cooling internal arrays down to cryogenic temperatures. The first stage array is cooled to approximately 77° Kelvin, condensing the water vapor and nitrogen while the other, colder array, cooled to approximately 15° Kelvin and coated with activated carbon, condenses and adsorbs the other gases. When the activated carbon reaches saturation, the pump needs to be regenerated. This cycle typically takes three hours. Regen times vary depending on the type of pump and if it has a heated purge. (Note: On Board pumps have the shortest regen cycle.)

Cryo pumps are considered hardy because they are not as susceptible to damage caused by over pressure or accidental venting of the pump to atmosphere. All that normally happens when the pressure gets too high is that the pump warms, temporarily losing its ability to pump and goes into regeneration. Cryo pumps do not pump helium well and do create vibrations that may interfere with some experiments. Cryo pumps have become the pumps of choice for the semiconductor and aerospace industries.

Things to consider in a cryo pump

• Temperature gage (diode vs. vapor pressure bulb)
• Compressor cooling (air or water)
• Power (single or three phase)