Voyager IV
Nitrox System
Nuvair www.nuvair.com
Page
27
Always use Oxygen Analyzers to monitor oxygen content of any gas flowing through the
System. Both air and Nitrox are subject to variations in oxygen content.
15.5 Shutting Down
1) When the Storage Banks are finished filling and tank valves are closed, the Nitrox System will
automatically shut down at the pressure set on the pressure switch (3600 psi).
2) Manually shut off the Membrane System by turning the Feed Air Regulator adjustment knob CCW
to reduce pressure to minimum setting and then turn off the LP & HP compressors.
3) The system will automatically drain all Filter, Compressor, and Volume Tank condensate.
16.0 Nitrox Operation Notes
16.1 Correlation of Feed air Pressure to Oxygen Content
After the 10 hour break-in period for your Nitrox System, you will notice that specific Nitrox %O
2
’s
always match specific feed air pressures once the System has warmed up. These pressures will be
repeatable. If you find that the Fill Oxygen Analyzer reads 36% O
2
when the feed air pressure is at
125 psi (9 bar), record this pressure or make a mark on the feed air pressure gauge indicating the
%O
2
. Do this for each %O
2
that you normally make, making sure System has warmed up first. The
next time Nitrox with 36% O
2
is needed, adjust the regulator to 125 psi (9 bar) and wait for the
Oxygen Analyzer reading to stabilize. You will find the analyzer reading to be very close to 36% O
2
,
requiring only minor adjustments of the regulator to achieve the exact desired %O
2
.
Use the Fill Oxygen Analyzer to verify the Nitrox oxygen percentage prior to pumping. When
using the feed air pressure reading to obtain specific oxygen percentage, minor adjustments
of the feed air pressure regulator may be required to obtain the exact percentage desired.
16.2 Hot Fills
While in the process of filling HP Nitrox Storage Tanks, you may have a need to supply a walk-in
customer with a Scuba Cylinder fill of a different Nitrox mix. You can change mixes as follows:
1) With the Nitrox System operating, isolate the HP Nitrox Storage Tanks from the HP Compressor
by closing the appropriate valves.
2) Record the Membrane System feed air pressure reading.
3) Slightly open fill whip valve on the HP Compressor, and adjust so the running Compressor
maintains 1500-2000 psi (100-140 bar) outlet pressure.
4) Adjust the B.P. feed air regulator to the pressure corresponding to the desired Nitrox %O
2
for the
Scuba Cylinder fill.
5) Allow the Fill Oxygen Analyzer reading to stabilize, make any minor adjustments necessary to
achieve the desired %O
2
, and then fill cylinder in normal manner.
6) When finished return regulator to previous setting, and allow the Fill Oxygen Analyzer reading to
stabilize. Make any minor adjustments necessary to achieve the desired %O
2
, and then resume
filling Storage Tanks.
