1、Lessons Learned Entry: 0541Lesson Info:a71 Lesson Number: 0541a71 Lesson Date: 1996-02-01a71 Submitting Organization: LARCa71 Submitted by: Ruth M. AmundsenSubject: Vacuum System Load and Ion Pump Selection Description of Driving Event: On MIDAS, an ion pump was purchased to be the maintaining pump
2、on a chamber before all vapor and leak loads within the chamber were calculated (or measured). This resulted in the ion pump being at its maximum pumping capacity during normal operation.Lesson(s) Learned: If a complete tally of all vacuum loads is not done before a pump is selected, the pump chosen
3、 may be over- or under-powered for the job.Recommendation(s): For vacuum systems, plan the load that will be on the pumping system by calculating all the surface areas of all materials exposed to the chamber, figuring the pressure load due to those materials based on their condition and tabulated va
4、lues of outgassing (can be found in several references). Add in loads due to leak rates. Then add some safety factor, and any de-rating of the pump necessary for temperature, power available, or aging, before selecting a pump for the chamber.Evidence of Recurrence Control Effectiveness: N/ADocuments
5、 Related to Lesson: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Mission Directorate(s): N/AAdditional Key Phrase(s): a71 Hardwarea71 Pressure VesselsAdditional Info: Approval Info: a71 Approval Date: 1997-05-05a71 Approval Name: Elijah C. Kenta71 Approval Organization: 421a71 Approval Phone Number: 757-864-3345Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
