35
Lib
er
at
ors
Repair Procedures
XII
RP25 – Flow Rate Test (Figure 24)
a.
Connect FCV (Item 24) outlet to flow meter (Item G) inlet
with respiratory tubing. Make sure flow meter outlet is open
and unobstructed and flow meter (Item G) is properly
positioned.
b. Verify internal operating pressure as per RP26. Vessels
internal operating pressure should
be between 19.5 psi (134
kPA) and 20.5 psi (141 kPA) before
beginning flow rate test.
This can be accomplished in
different ways:
Option A.) If reservoirs internal operating pressure is below
19.5 psi (134 kPA) let unit sit overnight after filling, with
FCV and vent valve closed, to stabilize to normal operating
pressure. Pressure should then be verified again prior to
performing flow test.
Option B.) If reservoirs internal pressure is above 20.5 psi
(141 kPA) allow unit to flow at a rate of 4 LPM for 1.5 hours
minimum prior to beginning the flow rate test.
Or
Option C.) If reservoirs internal pressure is above 20.5 psi
(141 kPA) open vent valve and wait for internal pressure to
stabilize at 20.5 psi (141 kPa). Ensure the
QDV pressure test
fixture gauge (Item H)
does not rise above 20.5 psi (141 kPa)
after FCV is closed.
This will indicate the tank is ready for
beginning the flow
rate test.
Test flow rate at each FCV (Item 24) position. Record all flow
rates.
d
. Flow rates must be nominal values within tolerances listed in
Table 9 or unit fails flow rate test.
NOTE: Flow rates will only be accurate if the reservoir is filled
properly. Reference the filling section of this manual for the cor-
rect pr
o
cedure.
RP26 – Operating Pressure Test (Figure 24)
a.
b.
Connect
QDV pressure test fixture (Item H)
.
Open
FCV
(Item 24) to 6 LPM setting.
Read operating pressure on
QDV pressure test fixture gauge
(Item H).
Operating pressure must be 1,2-1,5 bar (18-22 psig) or
unit
fails test.
RP27 – Flow Meter Verification (Figure 24)
a.
Flow meter
(Item G)
accuracy is best verified by a
calibration laboratory. Equipment should indicate liter per
minute oxygen gas
at atmospheric pressure and 21°C (70° F).
b.
Flow meter
(Item G)
accuracy may also be tested by
comparison to one
or more new, unused, calibrated flow
meters. This method
will increase confidence in accuracy of
readings, but not necessarily verify accuracy.
NOTE: If testing operating pressure because of improper
flow rates, test pressure immediately after flow rate test.
NOTE: For flow rate test Liberator needs to be at least 1/4 to
1/2 full of properly saturated liquid oxygen.
NOTE: Be careful to allow for accuracy tolerances of flow
meter. Table 9 does not account for these tolerances.
NOTE:
Factory flow rate s
pecifications are within the +/- 10%
tolerance required by ISO 18777 for environmental conditions
of temperature between 10
o
C – 32.2
o
C to (50
o
F – 90
o
F) and
elevations up to 527 m (1730 ft).
c.
FIGURE 24:
Flow and Pressure Tests
c
.
Liberators Technical Service Manual • PN 13350704 Rev
K
