CHAPTER 2. HYPERBARIC PRESSURE VESSELS
Section 1. TYPES OF HYPERBARIC PRESSURE VESSELS AND DESIGN PROCEDURES
SCOPE. This section presents general design information for those
pressure vessels (PV) which form a part of a shore-based hyperbaric facility.
The information includes a description of the included pressure vessels, and
a suggested series of technical disciplines and design procedures which can
form the basis of design for a structurally adequate pressure vessel. This
information is not to be construed as defining a required set of design
rules; neither is it to preclude the use of design procedures not
specifically detailed or mentioned here.
HYPERBARIC PRESSURE VESSELS. The hyperbaric pressure vessel is the
major component of the hyperbaric facility as it contains the subject and the
required controlled environment. The pressure vessel may be a single chamber
but more generally consists of two components, an inner chamber and an outer
lock or entrance chamber. For extended use, the PV may be a series of
chambers of various types for dry work, wet work, living, sleeping and
entrance under pressure.
TYPES OF HYPERBARIC PRESSURE VESSELS. Hyperbaric pressure vessels are
divided into three types according to the mission, They are:
Dry. A pressure vessel which has one or more chambers which
always contain gas.
Wet. A pressure vessel which has one or more chambers which
always contain fresh water or seawater.
Combination. A pressure vessel which has one or more chambers
which contain either gas or water at various times or a combination of gas
CLASSES OF HYPERBARIC PRESSURE VESSELS. Hyperbaric pressure vessels
are divided into two classes according to their planned use, They are:
Class I Man-Rated. A wet or dry or any combination pressure
vessel having, as its primary mission, human beings who are contained in and
subjected to a high-pressure environment. A chamber may be single or
Class II Non-Man-Rated. A wet or dry or any combination pressure
vessel not designed for human occupancy, but intended for the testing of
equipment or animals under hyperbaric conditions.
Pressure vessels are complex structures containing penetrations
for piping, hatches, viewports, and other appurtenances, as well as geometric
discontinuities such as cone-to-cylinder intersections and saddles for
pressure chambers are fabricated, such as modulus of elasticity, yield
strength, ultimate strength and fatigue strength and toughness, interact in a
complex fashion. Thus, the design of pressure chambers is usually complex.