through the servicing hose. This chemical drier
is provided to remove any moisture in the oxygen
supply. The oxygen flows into the bottom of the
drier, passes up through the drying agent, and out
through the servicing hose.
SERVICING HOSE AND LINE VALVE.
The servicing hose is a high-pressure, nonkinking,
metallic flexible hose. The line servicing valve is
attached to the servicing hose and is used to
control the flow of oxygen to the system being
The six supply cylinders are connected by
means of flexible hoses to their respective
control valves (fig. 5-14). The six control valves
are attached to the upper manifold. A pressure
gauge is screwed into each control valve at a point
below the seat. This allows each cylinder pressure
to be easily read.
The oxygen flows from the upper manifold
through either of two pressure regulators via two
The oxygen is collected in the lower manifold
where a gauge registers the pressure of the delivery
side of the system. The lower manifold is
connected by flexible hose to a drier, which filters
and dries the oxygen. The servicing hose connects
directly to the drier and has a line servicing valve
on the terminal end. The line servicing valve is
fitted with a standard oxygen cylinder connection.
The servicing trailer is capable of having its
cylinders recharged without removal. However,
many operating activities replace the empty
cylinders with full cylinders.
NOTE: NEVER completely expend the supply
of oxygen from a cylinder. Always leave a residual
pressure in excess of 50 psi.
REMOVAL OF EMPTY CYLINDERS.
When the trailer has been in use and cylinder
pressure is low, the cylinders are removed as
1. Close all lever valves on the manifold prior
to removing any cylinders.
2. Close the cylinder shutoff valves.
3. Disconnect the flexible hose that connects
the cylinder to the manifold.
Loosen the clamping arrangement that
holds the cylinders to the trailer.
Install the cylinder safety caps.
Remove the empty cylinders.
Do not attempt to remove empty cylinders
INSTALLATION OF FULL CYLIN-
DERS. The trailer should be loaded with
cylinders while fastened to a towing vehicle. If a
towing vehicle is not available, the rear stand
should be let down and hand brakes applied so
the weight of the cylinders will not cause the trailer
to tilt backwards. The retractable swivel wheel
should be down if the trailer is not hooked to a
towing vehicle. (When the trailer is hooked to the
towing vehicle, the swivel wheel should be
retracted.) Cylinders should be loaded from the
rear and should be handled with safety caps in
place. Standing cylinders should be brought to
within 4 feet of the rear end of the trailer. If the
cylinders are lying down, the safety cap end of
the cylinder should be just below the rear of the
trailer. The safety cap end of the cylinder should
be lifted or lowered and placed in the appropriate
channel. The bottom of the cylinder should be
raised and the cylinder worked into place.
Ensure that the cylinder is in its forward-most
position and firmly seated against the forward
cylinder stop. Remove the cylinder safety cap.
Position the cylinder so that the cylinder valve
outlet may be easily connected to the flexible hose
without causing undue strain on the hose. Prior
to connecting the hose to the cylinder, open the
cylinder. valve slightly to blow any foreign
matter from the outlet of the valve; then close the
valve. Connect the flexible hose nut to the power
cylinder valve. As soon as the cylinders are in
place and the hoses connected, the clamping
arrangement should be tightened.
The bottom four cylinders are clamped in pairs
by a wheel, and the top cylinders are tightened
by a single strap for each one.
After tightening the coupling nuts on the
hoses, the hoses should be free of twisting strain.
This strain can be prevented by gripping the hose
with one hand and twisting slightly in a clockwise
direction while tightening the coupling nut. When
the nut becomes tight, the hose will twist
(counterclockwise) slightly as it seats, and will stop
approximately at its neutral position.