Gas flow was set to purge level, purge valve opened, PMT assembly removed, blank flange bolted on to seal hole. Replacement on PMT assembly took ~60 minutss. PMT assembly reinserted and purge was continued for ~30 minutes more before closing purge valve and lowering rate to standard flow.
C4F8O cylinder weight at start of procedure: 189.0 lbs C4F8O cylinder weight at end of procedure: 183.0 lbs Old base: ser # 6595 Old PMT: ser # 276, Model 4508 New base: ser # 6667 New PMT: ser # 60311, Model 4572B (brand new UV glass PMT)