NOTE: Before starting this procedure, be sure to
CAUTION
don all of the appropriate safety clothing.
Monitor storage tank pressure gauge P-1 closely
1. Ensure that all control valves are closed, except
during cool down. Do not allow pressure in the
for the storage tank vent valve (GV-6).
storage tank to rise above 50 psi.
LV-1: The fill-drain line shutoff valve
LV-2: The transfer tank fill line shutoff valve
8. Monitor the storage tank liquid level gauge
GV-3: The transfer tank vent line shutoff valve
(LG-1) during filling. When the gauge reads 50 gallons,
or LOX starts to flow out of the vent manifold, close the
GV-4: The converter vent line shutoff valve
service valve on the supply tank.
GV-5: The transfer tank pressure buildup valve
9. Close the fill-drain line shutoff valve (LV-1).
2. Ensure that the trailer is level, the caster is down
10. Open the supply tank transfer hose vent valve,
and locked, and that the parking brake is set.
and disconnect the supply tank transfer hose from the
3. Place a clean, oil-free drip pan under the vent
servicing trailer.
valve.
11. Immediately drain the LOX that remains in the
4. Remove the dust covers from the supply tank's
supply tank transfer hose, and loosely replace the
transfer line, and purge the hose. (Purging the hose
coupling cap. Tighten the cap only after all LOX has
vaporized and bled off.
means to allow liquid LOX to flow through the hose,
cooling it until only liquid passes through, and no
vapor.)
WARNING
5. Connect the purged transfer hose to the fill-drain
Use extreme caution when disconnecting the
line coupling (C-1) on the servicing trailer.
transfer hose. Even though the hose has been
drained and the pressure relieved, some LOX
6. Open the servicing trailer's storage tank
will still remain. Do not direct the hose toward
fill-drain line shutoff valve (LV-1).
personnel or other equipment.
7. Slowly open the service valve on the supply
tank, allowing only a partial flow of LOX through the
12. Ensure that all control valves on the servicing
transfer hose and into the trailer. (Considerable
trailer are closed, except for the storage tank vent line
vaporization will take place until the transfer hose,
shutoff valve (GV-6).
fill-drain line, and storage tank of the servicing trailer
have cooled down.)
Filling of the storage tank is now completed.
Table 10-1.--LOX Servicing Trailer Controls and Indicators
Code
Component Name
Description of Function
C-1
Fill-Drain Line Coupling
Filling and draining point for the storage tank.
LF-1 Fill-Drain Line Filter
Prevents particles from flowing into the storage tank during filling.
LV-1 Fill-Drain Line Shutoff Valve
Controls the flow of LOX into the storage tank during filling. Also
used to drain the storage tank.
RV-3 Fill-Drain Line Relief Valve
Prevents excessive pressure buildup if the fill-drain line shutoff
valve and service valve of the central supply tank are closed with
cold gas or liquid trapped within the supply line.
GV-6 Storage Tank Vent Line Shutoff
Opened during filling and normal storage where overboard
Valve
discharge is available and safe. Normally closed during short
ground transportation.
10-7
