CHART CryoDoser FleX - Purging with Gaseous Nitrogen; Troubleshooting

18
Service and Maintenance Product Manual - CryoDoser FleX
™
LN
2
Dosing System
Troubleshooting
Refer to the table below for troubleshooting procedures. The table is arranged in a Symptom/Possible Cause/Solution format.
Note that possible causes for specic symptoms are listed in descending order of signicance. That is, check out the rst
cause listed before proceeding to the next. If you need further assistance please contact Chart’s service team at 1-408-371-
4932.
Symptom Possible Cause Solution
Liquid is coming out of the vent. The LN
2
supply pressure is too high.
Ice has developed inside the unit,
causing the inlet valve to malfunction.
Lower LN
2
supply pressure to 120 psi
(8.3 bar) or lower.
The CryoDoser FleX unit must be
drained of liquid, allowed to warm with a
continuous purge of warm nitrogen gas.
Contact Chart’s service team at 1-408-
371-4932 for a detailed procedure.
Liquid is coming out of the dosing head
even though the valve is closed.
The valve seat is contaminated (ice or
particles).
The CryoDoser FleX unit must be
drained of LN
2
. The dosing valve
assembly must be removed and
cleaned.
Contact Chart’s service team at 1-408-
371-4932 for a detailed procedure.
No liquid from the dosing head. There is insufcient liquid inside the
CryoDoser FleX unit.
The unit is disabled.
The nozzle is frozen shut.
The container detect sensor is not
detecting a container.
Check the level of LN
2
. If the level is
empty or low, open the supply valve.
Pull out the Dose Enable switch to
enable mode (ensure switch is not lit).
Run Insta-Purge to thaw nozzle.
Remove, clean, and re-install the
nozzle (see Nozzle Change Out section
for additional information).
Check sensor connections. Ensure
the sensor is correctly positioned to
detect points (gear tooth or the like).
If necessary, replace sensor, cable or
both.
Purging with Gaseous Nitrogen
The CryoDoser FleX
™
unit must only be purged with
gaseous nitrogen. Chart recommends the CryoDoser FleX
unit be purged when not in use. However, this may not be
practical for all operators. At a minimum, the CryoDoser
FleX unit should be purged after installation and prior to
startup to eliminate any water that may be inside the unit.
The CryoDoser FleX reservoir may also require purging
when there is liquid nitrogen owing out of the vent. The
CryoDoser FleX reservoir must also be purged when the
nozzle becomes frozen shut.
See the Dura-Cyl
®
Liquid Cylinder Fed System and
Bulk Tank (House Fed) System sections for additional
information.