Basic HTML Version
M
ost divers assume their cylinders are safe,
but few really understand the relevant
standards and maintenance practices. Do
you know what protocols are used to guide
the inspection of your life-support equipment? Do you know
how to safely handle and transport high-pressure cylinders?
You should know a lot about the care and proper use of
your cylinders because it is the owner (not the fill-station
operator, the dive center or the hydrostatic requalifier) who is
responsible for a cylinder’s condition.
StandardS
Cylinders are authorized for continued service when
inspected and tested to applicable standards by a formally
trained person. Inspection and testing are crucial because
a cylinder can be very dangerous when handled improperly
or inadequately maintained. High-pressure cylinders have
a tremendous amount of potential energy; an aluminum
80-cubic-foot cylinder, for example, has approximately
1.3 million foot-pounds potential energy. (One foot-pound
is the amount of energy applied to 1 pound to move it
1 foot.) Yet divers expose their cylinders to extremely harsh
conditions including salt water, high temperatures and
rough treatment without a second thought about the
potential risks.
Any cylinder containing more than 40 pounds per square
inch (psi) is considered high pressure according to the
Occupational Safety and Health Administration (OSHA).
Most divers are familiar with the hydrostatic requalification
(commonly referred to as “hydro”) federal regulations require
of solid-wall cylinders every five years. Many believe if a
cylinder passes the requalification it is safe, but the truth is
that more cylinders fail visual inspection than hydrostatic
retesting. Some divers erroneously believe visual inspections
are a method for dive centers to make money and there are
no formal requirements. In fact, the dive industry established
annual visual inspection using a practice backed up by the
Compressed Gas Association (CGA).
Know your cylinder
How can divers quickly determine whether a cylinder is
fit for service? A cursory inspection should be performed
each time a cylinder is handled. Compare the cylinder you
are about to use to a new one. (It’s OK to imagine a new
one if there is not one nearby.) Does it appear undamaged?
Does it make any noise, such as a rattle or sounds of air
escaping? Cylinders should never make sounds when lifted
or transported. If there is a rattling or sloshing sound, there is
most likely something wrong.
Tank Safety
Care and handling of high-pressure cylinders
T E X T B y M a r k a . G r E s h a M / P h O T O s B y s T E P h E N F r I N k
46
|
sPrING 2012
RESEARCH, EDUCATION & MEDICINE
//
S A F E T Y 1 0 1