kyle.ryan@LIGO.ORG - posted 11:38, Friday 08 June 2018 - last comment - 17:06, Friday 08 June 2018(42403)
Changed pumping configuration in the Corner Station in preparation for opening Y-arm this Monday
I valved-in IP2, IP5, IP3 and IP4 and, concurrently, valved-out the YBM, XBM and Vertex turbo pumps. Additionally, I connected a pump cart to GV5's annulus pump port and removed the pump cart from IP3. Assuming the IPs stabilize and GV5's AIP can run unassisted, we should be ready to open the Y-arm on Monday,
Water vapor has gone down, but hydrocarbon and H2 levels have gone up.
Valving out each IP one by one to see if one contributes more than others. Attached is scan with IP2 valved out.No noticeable change after 20 minutes. IP2 is not refurbished; all others are rebuilt and were baked out by vendor. New isolation GVs were not baked out.
IP3 isolated for 35 min. No change.
IP4 isolated for 15 min. No change.
IP5 isolated for 15 min. No change.
There may be small changes in partial pressures during each test, and given longer isolation durations, may be more obvious. I was quickly looking for a show stopper. IP 2,3,4,5 all valved back in.