AVS 51st International Symposium
    Vacuum Technology Tuesday Sessions
       Session VT-TuP

Paper VT-TuP3
Continued Vacuum Pump Oil Testing at the National Synchrotron Light Source to Minimize Oil Waste@footnote 1@

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: J.-P. Hu, Brookhaven National Laboratory
Authors: C.L. Foerster, Brookhaven National Laboratory
J.-P. Hu, Brookhaven National Laboratory
E. Haas, Brookhaven National Laboratory
Correspondent: Click to Email
An oil-testing project was established to determine if synthetic vacuum pump oil could be used effectively to reduce the large amount of oil waste produced during normal operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL). More than two hundred oil-sealed rotary vane pumps are used at the NSLS facility, such that a longer oil change interval would greatly reduce maintenance costs as well as oil waste. Initial pump oil waste was approximately 75 gallons per year. Two basic types of vacuum pump oils, mineral and synthetic, are being tested for a direct comparison. Three of the same size two-stage mechanical pumps were set up and run simultaneously having the same gas load. Convectron gauges, cold cathode gauges, and isolation valves were connected to a central vacuum chamber having a common inlet pressure control and a sampling valve for residual gas analysis. To simulate oil degradation produced by long-term mechanical pump operation, the system air load was manually controlled, with an air bleed valve in a common vacuum chamber, which was periodically adjusted, to run the pumps at a 500 mTorr inlet pressure. Vacuum pump oil suppliers to expedite the oil viscosity change, acid buildup, and pump-wear debris production suggested the pressure for mechanical pump testing. At this inlet pressure, the testing time is reduced and any oil back streaming is minimized. After one and a half years of running there have been no significant changes in either of the oil types. The detailed test data for the resulting oil properties, oil degradation, visual comparison, vacuum conditions, and pump characteristics will be presented for comparison of the pump oils used at NSLS and for estimation of the resulting oil waste reduction.@footnote 1@ Work performed under the auspices of the U.S. Department of Energy, under contract DE-AC02-98CH10886.