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 shutoff valves. 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.

Loading Cylinders

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 described below.

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.

4. Loosen the clamping arrangement that holds the cylinders to the trailer.

5. Install the cylinder safety caps

6. Remove the empty cylinders.

CAUTION Do not attempt to remove empty cylinders while charging.