Check this page before and after the system is restarted → Operational Configuration

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
QT PLC (only) restart procedure	How to restart the QT PLC
Cooldown	Look At Updated Page
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 QT-HMI has an alram window opened and showing the codes 603 and 602	It's a known warning from some software development → close the window	HR3 Tripped Warning Message
If the QT-HMI got frozen		How to fix the QT-HMI if its screen got frozen
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
If FCA and FCB shows strange values (like 71.11slm on both)	Probably a consequence of radiation damage	How to fix if the outlet flows of Liquefiers are showing strange values
If the coldhead compressors show Alarm due to high temperatures of LCW	Higher outside temperatures	How to clear the coldhead compressor LCW temperature alarm

The volume of an outside gHe tank: 1600 cubic feet (V = 45306.95 L)
100 slm rate on Magnet FC is equivalent to ~ 192 LHe liters per day (i.e. assuming both LQ A and B are running)

Cryofab : https://www.cryofab.com/contact
Call +1 (800) 426-2186 and ask for extension #14 (Mr. Tam)
Tell this serial number and he will recognize us