HELIX CTI-CRYOGENICS CRYO-TORR 100 Installation, Operation And Servicing Instructions page 41

Problem
I) High base pressure of
vacuum system; cryopump
temperature below 20K.
2) High base pressure of
vacuum system. and a
cryopump temperature
above20K.
en-CRYOGENICS
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HELIX TECHNOLOGY CORPORATION
Table A.1 Troubleshooting the Cryopump
Possible Cause
1)
Air-to·vacuum leak in
vacuum system.
2) High partial pressure of
non-condensables (helium.
hydrogen. or neon) within
the cryopump because the
15K array has reached full
eapacity.
3) A leak through a roughing
valve. purge valve. or other
accessory.
1)
Decrease in cryopump
cold head performance.
2)
High partial pressure of
non-condensables (helium.
hydrogen. or neon) within
the cryopump.
3)
Excessive thermal load on
frontal array.
A-3
Corrective Action
I) Check the following:
a. Vacuum chamber and
Hi-Vac valve for leaks.
b. Cryopump for leaks.
c. Cryopump relief valve for
leaks.
2) Regenerate the cryopump.
3) Check all valves to insure
proper seating.
1)
Check compressor gauge for
low helium charge pressure.
Add gas as necessary.
2)
Regenerate the cryopump.
3) Reduce the thermal radiation
load by:
a. Shielding the cryopump.
b. Lowering the temperature of
the radiating surface.