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Lib
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RP33 – Determining Liquid and Gaseous Oxygen Capacity
1.
Weigh the empty reservoir and record the weight (kg/lb)
2.
Fill the unit with properly saturated liquid oxygen (Per
Filling Procedure in Operation section of manual)
3.
Weigh the full reservoir and record the weight (kg/lb)
4.
Subtract the empty reservoir weight (STEP 1) from the
full
reservoir weight (STEP 3) to determine the weight of
liquid
oxygen that is inside of the reservoir
5.
Take the weight of liquid oxygen (calculated in STEP 4)
and
divide it by the LOX density to calculate the liters of
liquid
oxygen in the reservoir
NOTE: The density of liquid oxygen will vary based on opera-
tion and saturation pressures. The densities provided in the
specifications section of this manual, which are to be used in
the above calculation, are representative of optimum opera-
tion and saturation pressures. Due to rounding and conver-
sion accuracy, a range of 0.10 L is acceptable in calculation.
NOTE: If proper filling procedures (primarily source pressure)
are not followed per the filling procedure in operation sec-
tion of this manual, reservoir will not be at nominal pressure
immediately following the fill process. In addition, if PRV, SRV
and/or Economizer are not performing within ranges speci-
fied in the Specifications section of this manual, the reservoir
will not be at nominal pressure immediately following the fill
process. If either or both of these conditions occur, calcula-
tions using the nominal densities listed in the Specifications
section of this manual, will not be accurate.
Example: Calculation of Liquid O
x
ygen in a full Liberator 45
reservoir
1.
Empty weight of LIB 45 Reservoir: 24,95 kg (55.00 lbs)
2.
Filled unit with properly saturated liquid oxygen
3.
Full weight of LIB 45 Reservoir: 7
4.99
kg (16
5.32
lbs)
4.
7
4.99
kg (16
5.32
lbs) – 24,95 kg (55.00 lbs) = 50,
04
kg
(11
0.3
lbs)
5A. 5
5.04
kg/1.095
kg/L = 4
5.7
Liquid Liters of Oxygen
5B. 11
0.3
lbs/2.413
lbs/L = 4
5.7
Liquid Liters of Oxygen
d. Remove dewar cap from the new dewar and place the cap on old
dewar.
e. Clean/dry both the probe and dewar following procedure in
section VIII.
f. Connect the manifold assembly with coils to the new dewar;
be sure to follow the manifold assembly replacement proce-
dure (See RP9). Do not replace shroud.
g. Replace condensate bottle (Item 56), bracket (Item 57) and
drain tube (Item 58).
h. Scribe part number and serial number on new dewar handle.
Make part number and serial number on old dewar illegible.
i. Calibrate meter by following RP7.
RP32 – Normal Evaporation Rate Test
a. Fill the unit with at least 9 to 11 kgs (20 to 25 lbs) of properly
saturated liquid oxygen.
b. Allow unit to sit undisturbed for a minimum of 12 hours with
the FCV in Off position and the vent closed.
c. Weigh unit. Record weight and time.
d. Allow unit to sit undisturbed for a minimum of 24 hours.
e. Weigh unit. Record weight and time.
f. Calculate liquid loss rate (NER) using the following formula:
Weight lost (kg or lbs)
NER = —————————— x 24 hours/day
Elapsed time in hrs.
Example
0.63 kg
NER = ————— x 24 hours/day
25.5 hrs.
NER = 0,59 kg/day
g. If NER is more than 0,9 kg/day (2 lbs/day) for a Liberator,
the dealer may want to send the unit to CAIRE, Inc. for re-
evacuation. If NER is more than 2,3 kg/day (5 lbs/day) the
dealer should remove the unit from service and have the unit
re-vacuumed.
NOTE: Scale must be accurate to ± 0.02 kg (0.05 lbs).
Liberators Technical Service Manual • PN 13350704 Rev
K
