8. TRANSFER TANK PRESSURE GAUGE (P-2)
1. STORAGE TANK PRESSURE GAUGE (P-1)
9. CONVERTER FULL INDICATOR GAUGE (F1)
2. STORAGE TANK LIQUID LEVEL GAUGE (LG-1)
10. FILL-DRAIN LINE SHUTOFF VALVE (LV-1)
3. CONVERTER VENT LINE SHUTOFF VALVE (GV-4)
11. STORAGE TANK VENT LINE SHUTOFF VALVE (GV-6)
4. TRANSFER TANK VENT LINE SHUTOFF VALVE (GV-3)
12. FILLER VALVE (C-2)
5. TRANSFER TANK FILL LINE SHUTOFF VALVE (LV-2)
13. CONVERTER VENT LINE CONNECTION (C-3)
6. TRANSFER TANK PRESSURE BUILDUP VALVE (GV-5)
14. FILL-DRAIN LINE COUPLING (C-1)
7. TRANSFER TANK LIQUID LEVEL GAUGE (LG-2)
Figure 8-2.--Liquid oxygen servicing trailer controls and indicators.
TRANSFER TANK PRESSURE GAUGE.--
TRANSFER TANK FILL LINE SHUTOFF
(Fig. 8-2, item 8). The pressure gauge indicates the
VALVE.--(Fig. 8-2, item 5). The valve is used to
pressure in the transfer tank. The pressure in the
control the gravity flow of liquid oxygen from the
transfer tank must be greater than the pressure in the
storage tank to the transfer tank.
storage tank to achieve transfer of liquid since the
TRANSFER TANK PRESSURE BUILDUP
converter is vented into the storage tank during
VALVE.--(Fig. 8-2, item 6). The pressure buildup
converter fill operation. The gauge is calibrated to read
valve controls the flow of liquid oxygen from the
0 to 160 psig. Safe operating pressure is 0 to 90 psig and
bottom of the transfer tank to the pressure buildup
is indicated by a green band; a red band indicates unsafe
(PBU) coil. The PBU coil is a heat exchanger where the
pressure of 90 to 160 psig.
liquid oxygen is exposed to ambient temperature and is
converted to gas. As the liquid changes to gas it
CONVERTER FULL INDICATOR GAUGE.--
expands. The output gas of the PBU coil is fed back to
(Fig. 8-2, item 9). The full indicator gauge (marked
the transfer tank vapor space, providing pressure to
LIQUID-GAS) is a vapor pressure thermometer
discharge liquid to the converter. This valve is open
that monitors the converter vent line temperature.
only when pressure is required to fill the converter.
During transfer of liquid to a converter, the gauge
indicates GAS temperature in the converter fill
TRANSFER TANK LIQUID LEVEL GAUGE.--
line. When the converter is full, the vent line is
(Fig. 8-2, item 7). The liquid level gauge indicates the
filled with liquid oxygen overflow. The converter
level of liquid oxygen in the transfer tank. The gauge is
vent line temperature drops and the gauge indicator
magnetically and mechanically coupled to a float
moves to the LIQUID position and indicates a full
sensor inside the transfer tank. The gauge is calibrated
converter.
in percent of full.
8-3
