TM 5-4220-233-14
Section II. EQUIPMENT DESCRIPTION
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Equipment Characteristics, Capabilities and Features ...........................................
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Location and Description of Major Components.....................................................
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Equipment and Transportability Data..................................................................... 1-10
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EQUIPMENT CHARACTERISTICS, CAPABILITIES AND FEATURES.
a.
The Mobile Compressed Gas Servicing Unit consists of two major assemblies. The Body Assembly
contains the Compressed Gas System and the Trailer Assembly which provides for unit mobility. The entire
unit is in the 2-1/2 Ton weight class for cross country surface movement.
b.
The Body assembly contains the Compressed Gas System and is used to simultaneously charge up to four
twin 80 cubic foot SCUBA cylinders with breathing air at a maximum rate of 400 psi per minute. The Body
Assembly is equipped with the following items:
(1) An aluminum frame weldment that provides the support for the storage cylinders, cylinder clamping
system, control panel, front doors, side access panels and filling trough.
(2) Eight DOT3AA rated storage cylinders each capable of holding a maximum of 422 SCF @ 70° F (59.4° C)
of breathing air at 5,000 psi (34,400 kpa). A shutoff valve is mounted at the neck of the cylinder. The shutoff
valves have a CGA347 outlet connection and contain an internal safety plug that automatically vents if the
pressure in the storage cylinder exceeds safe limits.
(3) A cylinder clamping system consisting of two 1-1/2 inch wide band clamps for each cylinder and a retaining
bar at the rear of the cylinders that secures one row of four cylinders. The clamping allows the removal of any
or all the cylinders without the use of hand tools.
(4) A control panel mounted at the front of the Body Assembly behind the front doors contains the gauges,
valves, tubing, and hoses to recharge the storage cylinders, service up to four SCUBA cylinders. The inlet and
outlet connections on the control panel are CGA347 high pressure air connections. Four, fifteen foot long fill
hoses with yoke adapters are included to interface with "J" or "K" type connections on the SCUBA cylinders.
(5) Two hinged doors are mounted at the front of the Body Assembly to provide protection for the control
panel. The roadside door contains a weather-proof toolbox dedicated for storage of tools and spare parts
necessary to repair the Compressed Gas System components only.
(6) Side access panels with 1/4 turn fasteners are provided for easy access to the backside of the control panel
and the storage cylinder shutoff valves.
(7) A filling trough is provided to prevent SCUBA cylinders from over-heating during the filling process. The
trough is sized to allow filling of four sets of twin 80 SCUBA tanks simultaneously. When not in use, the trough
Is secured to a mounting base on the curb side of the frame.
c.
The Trailer Assembly is designed to provide a firm foundation for the Body Assembly during both highway
and off-road travel and operational site jacking. The Trailer Assembly consists of the following.
(1) A welded steel chassis that includes an A-frame type drawbar. The chassis provides the foundation to
support the Body Assembly as well as the trailer axle, suspension, brake system, electrical system and
accessory components. The chassis also contains the Servicing Unit's lifting/tiedown provisions
(2) A single beam type axle assembly rated at 5,000 lbs. The axle assembly provides the foundation for the
two-wheel running gear and suspension.
(3
A suspension system rated at 5,000 lbs. consisting of a set of leaf springs and double-acting telescopic
shock absorbers.
(4) A brake system that consists of surge actuated hydraulic service brakes with interface to an operator
actuated mechanical parking brake. The service brakes also provide for automatic (emergency) brake
application in the event that the trailer breaks away from the towing vehicle.
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