TM 5-4220-227-14
Section III. PRINCIPLES OF OPERATION
1-11. Technical Principles of Operation. The following describes the theory of operation of the 3-Person
Recompression Chamber.
a. Environmental Control. Figures 1-3 and 1-4 provide the flow and electrical diagrams of the 3-Person
Recompression Chamber. The Recompression Chamber provides a controlled pressurized enclosure for the treatment
of physiological disorders caused by inability of the human body to adjust to pressure changes. Air pressure in the outer
and inner lock is controlled by air supply and air vent valves located in the external control panel. An external
heater/chiller module supplies the internal heater/chiller unit with cooling/heating fluids to heat or cool the I/L of the
chamber. The oxygen bottles with manifold, supplies the chamber with the needed oxygen.
b. Electrical and Communications Operation. Power for the chamber electrical system is brought to the unit through
the GFI located outside of the chamber. A primary communications intercom system and internal speakers are the
source of communications between personnel inside and outside of chamber. The chamber is supplied with a pressure
relief safety valve, set to relieve when the internal pressure reaches 105 PSIG.
1-12. ASME Certification.
a. In accordance with the requirements of MIL-C-52988(ME) the recompression chambers are designed, fabricated,
tested and certified in accordance with the requirements of the American Society of Mechanical Engineering (ASME)
Code. The units are all registered with the National Board of Boiler and Pressure Vessel Inspectors, 1055 Crupper Ave.,
Columbus, Ohio 43229, phone number 614-888-8320.
b. Each unit is equipped with a welded in place, ASME Code nameplate, located on the chamber shell to the right of
the control cabinet. This nameplate has the National Board registration number for each unit, which corresponds to the
ASME Data Form U-1, manufacturers data report, filed for each unit.
c. Should it ever be required to obtain information concerning modifications or repairs to the pressure boundary of
the chamber and it is deemed necessary to make the necessary repair or modifications in accordance with ASME Code
and National Board requirements, it is advisable to contact the National Board.
d. The above information is included in this manual to inform all using personnel of these requirements from a safety
aspect and also if it is desired to not void any ASME Code certifications.
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