MECHANICAL & HYPERBARICS
CASE M1 - Raceway Tubing for Hyperbaric Complex, T. Hayes
Problem: Thin walled stainless steel tubing used as electrical raceway in
hyperbaric facility complex.
Collection of Facts: In an effort to keep carbon steel out of the hyperbaric
environment, the contractor installed thin walled stainless steel tubing as
electrical raceway. When bends were made in the tubing, it crimped. Cable
was pulled anyway causing it to chafe. Rigid steel conduit or EMT should have
been installed. Neither creates a hazard in a hyperbaric environment.
Solution: The stainless steel tubing was removed and replaced with rigid
CASE M2 - Submersible Pump for Fire Protection (Hyperbaric), T. Hayes
Problem: 220 volt submersible fire pump installed in bilge area of hyperbaric
Collection of Facts: As a solution to fire protection requirements, the bilge
area of the chamber complex was filled with water, and submersible fire pumps
were installed. This was the supply for the deluge system within the
chamber. The fire pumps posed a hazard as a shock and fire hazard, and
stagnant water pose a health hazard.
Solution: The deluge system should be supplied by a pressurized water tank
located outside of the chamber.
CASE M3 - Air of Manned Chambers, T. Hayes
Problem: Large volumes of air are required for ventilating manned hyperbaric
Collection of Facts: For standard recompression chambers, 48,502 SCF of air
is required by the U.S. Diving Manual for ventilation to remove CO2 and O2
build-up when the complex is used for the most severe diving requirements.
Usually this air is provided by charged high pressure air flask. These flasks
themselves are expansive, costly to maintain, and utilize valuable building
space. The required number of flasks could be reduced, if the CO2 and O2
build-up in the chamber could be reduced. One method to accomplish this
reduced build-up would be to pass CO2 and excess O2 directly out of the
chamber through the inhalator which is provided with an overboard discharge.
The Navy has recently approved use of such an inhalator which is manufactured
Solution: Activities having hyperbaric facilities and wishing to reduce air
flask procurement and maintenance costs should consider installing the
approved overboard discharge systems.