Image RemovedImage Added

QT System

1. Check the purity of the outside gHe tanks, and regenerate/refill (max. pressure 145 psig, and min. 25 psig).
   Note: It's better to keep the tube trailer at this stage because you may need to refill the gHe tank as the Liquefiers produce LHe.
2. Clean up Dewars and the level-sensor tubes.
3. Confirm all transfer lines' vacuum jackets are pumped down to 1 x 10^(-3) Torr in Pressure and < 1 x 10^-9 mbarL/s leak-rate.
4. Leak-check all QT-system piping.
5. Regenerate the purifier.
6. Check F1, F2, F3 filters, oil filter, and oil level on HR3 and perform maintenance if required based on the scheduled maintenance.
7. Check and confirm that LCW supply is available to the cold-head compressors.
8. Check the cold-head compressor pressures' gauges and confirm 100 psi (IN) ~300 psi (OUT) (i.e. ~200 psi difference on both gauges in each compressor).
   If not, pressurize the cold-head compressors using the HA.
9. Check LCW Temperatures on the meters right next to the staircase and also via https://e906-gat1.fnal.gov/data-summary/e1039/slow-cont-acnet.php?G_NM4LCW=on.
   Ensure T_in (NM4LCWT2) < 95F or T_out (NM4LCWT1) < 115F or any suspicious behavior in LCW flow, pressures, or temperatures. If there is a concern, then DO NOT PROCEED. Contact the Target Expert and Run Coordinator.
10. Ensure the valve configuration is set according to the Operational Configuration's Table.
11. Ensure the purifier's LN2 space is between 70%-90% (see LN2 fill procedure).
12. Go to the main menu → Helium Compressors → Ensure to have "ON" state on both "Enable" and "Remote" columns for both LQ A and B.
13. Set  (a) the Full system to  "Run  + Auto", and. (b) each liquefier to  "Run+ Manual + Liquefy mode (Manual + Idle mode is also the same because Liquefy/Idle option has no effect when it is in the 'Manual' mode)
14. Ensure the dewar pressure alarm threshold is around 0.2 psi on both Liquefiers (navigate to the Liquefier 'Settings' to check that).
15. Set the inlet flow to 60slm: enter 60slm on FC501(A/B)Q (then press enter)
16.  Set the outlet flow for the maximum flow by opening SVV(A/B) and the manual (bypass) hand valves NV502 (A/B).
17. Open the magic valve NV501A/B completely (~9 turns)
18. Turn ON the cold heads manually on "Helium Compressors" screen.
    It will take about 2 hrs and 30 mins for the cold head temperatures to reach 4 Kelvin.
19. Once cold head temperatures reach 4 Kelvin, then gradually close NV502 (A/B) bypass hand valve while watching the Dewar pressure.
20. Once the Dewar pressure is > 6.5 psi from Step 7, then close SVVB and immediately open SVNB and ensure the FCBQMC is 60slm (FCBQ will also show 60slm). Then leave NV502 (A/B) opened.
    Then you will see FCBI starts increasing and should go up to 60slm or, at least 40slm (or above).
21. Let it run in this configuration: in-flow 60slm, out-flow 60slm (via SVNA/B), cold-heads are running, mode: run+manual+liquefy
22.  You should expect ice/frost on Dewar neck during this phase, and you will have to use the heat gun to melt the frost.
23.  When you start seeing FCBI start going down while FC501B is 60slm, then lower the value of FCBQMC step by step based on the FCBI.
24.  Once you bring FCBQMC down < 5slm, then check the Liquefier Settings screen to ensure the following values.
    
25. Switch the Liquefier to Run + Auto + Liquefy mode.
    
26. Bring the magic valve NV501A/B  position for optimizing for production ( open ~1/2 a turn).
27. Keep monitoring the system.
28. Ensure there is enough gHe in the tank during the LHe production mode (at least above 60 psi when both Liquefiers are running).
    If not, switch the Liquefiers to "Run+Auto+Idle" mode, and arrange a gHe tube trailer to refill as soon as possible.
29. Keep monitoring the following parameters frequently.
    (a) inlet flows to both Liquefiers: should be > 40slm.
    (b) outlet flow from both Liquefiers: should be < 5 slm.
    (c) refill LN2 to the purifier as needed (usually it has been filled once every other day).
    (d) cold-head temperatures: should be around 4 Kelvin (it can go up to ~6-7 Kelvin when coldhead heaters are on automatically time-to-time).
    (e) if there is a "blocking alarm" on coldheads. (if "yes", then see Resolving Liquefier Blocking Alarm when Liquefier is on Liquefy Mode).
    (f) calculate LHe production rate, and confirm it is approximately ~ 4L /hr or higher.
30. Ensure P40 and P41 pressure gauges on HR3 front panel have a pressure difference of less than ~40 psi when both Liquefiers are running.
    It will be ~20 psi difference when only one Liquefier is running. If the difference is larger than those values, then a purifier regeneration is needed.
31. It will roughly take about ~54 hrs + a few hours to fill both Dewars 210L each.
32. Ensure both Liquefiers are automatically switched to "Run+Auto+Idle" mode.

...