Operational Configuration (←Click)

Routine Maintenance Procedures

Purpose	Instructions/Links
Cleaning (Liquefier)	Dewar Cleaning Procedure (using the transfer line) Dewar Cleaning Procedure (using the outlet MFC and its bypass) Liquefier Cleaning when Dewar contains LHe
Cleaning (Purifier)	Cleaning QT purifier Helium-space (pumping-purging the purifier) Cleaning QT purifier LN2 space
Cleaning (HR3 piping)	Purging HR3 after a maintenance
Cleaning the buffer tank	Cleaning the Buffer Tank on the Cryoplatform
Cleaning the filters F1, F2, F3, and the filter before MV101	Cleaning the filters F1, F2 at HR3 Cleaning the filter at MV101
Fills	Filling LN2 to the purifier using the outside LN2 tank Filling LN2 to the purifier using a portable Dewar
Taking purity measurements at various places in the system	Measuring gHe purity

Purpose	Instructions/Links
System Startup Procedure	QT System Starting Procedure
Cooldown	Dewar Cooldown Procedure
For planned power outage	Shut Down and Restart Procedures
Taking purity measurements at various places in the system	Measuring gHe purity

Issue	Reason	What to do?
If the Dewar level indicators have large fluctuations	Level sensor tubes are contaminated	Fixing dewar level indicator FNAL Approved procedure: https://seaquest-docdb.fnal.gov/cgi-bin/sso/ShowDocument?docid=10401
Coldheads blocking alarm	Possible contamination or cold heads have been running so long without any intake gHe for a while	Resolving Liquefier Blocking Alarm when Liquefier is on Liquefy Mode Resolving Liquefier Blocking Alarm when Liquefier is on Idle Mode