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Companion Portable Technical Service Manual • PN 20562220 Rev B
27
Companion P
or
tables
Troubleshooting & Repair Procedures
XI
Symptom
Probable Cause
Corrective Action
8) Low flow at all
LPM settings
a) Nasal cannula kinked or
leaking
Inspect the functionality of the nasal cannula.
b) Saturation pressure is too
low
Inspect the saturation pressure of the reservoir used for filling. Allow at
least 30 minutes at no flow for the portable to saturate properly.
c) Leak in the system
Perform a leak check on the plumbing (RP2). Repair leaks as necessary.
d) Flow control valve inlet
filter screen dirty
Clean or replace (RP20) the filter screen.
e) PRV faulty
Test the PRV (RP9) and replace (RP10) if necessary.
f) Blockage in the liquid
withdrawal circuit
Check the warming coils and withdrawal tubes for blockages. Replace if
necessary.
g) FCV faulty
Replace the FCV (RP20)
9) Increased NER
a) Saturation Pressure is too
high
Inspect the saturation pressure of the reservoir used for filling. Allow at
least 30 minutes at no flow for the portable to saturate properly.
b) Leak in the system
Perform a leak check on the plumbing (RP2). Repair leaks as necessary.
c) Relief valve open
Ensure that there is no venting from the relief valves. If there is refer to
the corrective actions for “Excessive venting from relief valves (hissing
sound)”
d) Partial or complete loss of
vacuum
Conduct the NER test (RP23) and return the unit to CAIRE, Inc. if neces-
sary.
10) Excessive Frost
NOTE: Minimal
frost on the case and
on the plubming is
normal. This symp-
tom applies to frost
that is much greater
than what is nor-
mally observed.
a) Frost is acceptable
Some frost on the outer case and on the plumbing is acceptable, espe-
cially at high flow rates during continuous use. This is due to the evapo-
ration of LOX to gas and the temperature difference between the LOX
and room temperature.
b) High humidity level
High humidity levels can increase frost accumulation.
c) Saturation pressure is too
high
Inspect the saturation pressure of the reservoir used for filling. Allow at
least 30 minutes at no flow for the portable to saturate properly.
d) Leak in the system
Perform a leak check on the plumbing (RP2). Repair leaks as necessary.
e) Relief valve open
Ensure that there is no venting from the relief valves. If there is refer to
the corrective actions for “Excessive venting from relief valves (hissing
sound)”
f) Partial or complete loss of
vacuum
Conduct the NER test (RP23) and return the unit to CAIRE, inc. if neces-
sary.
11) Unit will not main-
tain acceptable pres-
sure when in use
a) Saturation pressure is out
of specification
Inspect the saturation pressure of the reservoir used for filling. Allow at
least 30 minutes at no flow for the portable to saturate properly.
b) Leak in the system
Perform a leak check on the plumbing (RP2). Repair leaks as necessary.
c) PRV faulty
Test the PRV (RP9) and replace (RP10) if necessary.
Table 8
(cont.)