AVS 53rd International Symposium
    Vacuum Technology Tuesday Sessions
       Session VT-TuP

Paper VT-TuP1
Vacuum Pump Oil Testing to Minimize Oil Waste at the National Synchrotron Light Source*

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Vacuum Technology Poster Session
Presenter: E.-P. Hu, Brookhaven National Laboratory
Authors: C.L. Foerster, Brookhaven National Laboratory
E.-P. Hu, Brookhaven National Laboratory
E. Haas, Brookhaven National Laboratory
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An oil-testing project was established three and a half years ago to determine if synthetic vacuum pump oil could be used effectively to reduce some of oil waste produced during normal operation of storage rings and beam lines in the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL). More than two hundred oil-sealed rotary vane pumps are currently used at the NSLS facility, such that a longer oil change interval would greatly reduce maintenance costs as well as oil waste. Prior to this project the mechanical vacuum 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 two-stage mechanical pumps were set up and run simultaneously. Convectron gauges, cold cathode gauges, and isolation valves were connected to a central vacuum chamber with a common inlet pressure control and an RGA sampling valve. To simulate long-term mechanical pump operation, the system gas load was constantly adjusted at an inlet pressure of 500 mTorr using an air bleed valve. This inlet pressure was suggested by the suppliers of vacuum pump oil to expedite the oil viscosity change, acid buildup, and pump-wear debris production under minimal risk of oil backstreaming in the test pump. After three and a half years of continuous running there have been no significant changes in either of the oil types. Detailed test data for the resulting oil properties, oil degradation, visual comparison, vacuum conditions, and pump characteristics will be presented for evaluation of the pump oils used at NSLS and for estimation of the resulting oil waste reduction.@FootnoteText@*This research is supported by the U.S. DOE under the contract DE-AC02-98CH10886.