DOT Rule Change Would Require That SCBA Composite
Cylinders Be Condemned If Exposed to 350 Degrees Heat
By: David
White
Publisher
Industrial Fire World
If your job requires
wearing a high pressure air cylinder in close proximity to open flames, the
U.S. Department of Transportation wants to help you. No, that does not mean the
DOT is going to show up with an extra hand line or a tanker full of foam. That
is a little too specific for most bureaucrats.
Like any government
agency, the DOT is better at inventing one-size-fits-all solutions to slay
dragons that do not even exist. In this case, the imaginary dragon being
stalked is the danger connected with high pressure cylinders. Such cylinders
have a wide variety of industrial uses aside from self-contained breathing
apparatus for firefighters. And, industry-wide, we are unaware of any great
rash of cylinder-related catastrophes that would merit DOT intervention.
However, under a rule change proposed by DOT, the applied standards
covering all high pressure cylinders will be radically altered.
Firefighters generally prefer SCBA cylinders made
from lighter composite materials. Be aware that under the new DOT rule a
composite cylinder exposed to 350 degrees F or greater must be automatically
condemned. That does not mean somebody is going to hurl obscenities at it. That
means trashed, discarded and thrown away.
No fire worth donning an
airpack to battle would generate less than 350 degrees heat. Forget about a
minimum exposure time. One second of exposure treated the same as a full hour.
The only problem this rule change solves is that refilling used cylinders will
no longer be necessary. Simply chunk 'em in the dumpster and be done with
it.
For years, SCBA airpacks have been subject to
hydrostatic testing at regular intervals determined by the type of cylinder in
use. Furthermore, the valve must be pulled and the inside thoroughly inspected.
Under the proposed rule change, hydrostatic testing would be
abandoned in favor of ultrasonic. The fact that ultrasonic is much more
expensive and not effective in detecting flaws in cylinders with flat bottoms
or hemispherical ends has not deterred the DOT. Yet, despite the insistance on
ultrasonic, the new standard could hardly be called more stringent. Only a 90
percent sampling of cylinders would be subject to the new testing. Internal
inspections will no longer be required, even if experience teaches that most
SCBA corrosion problems begin inside.
Under the new rule, high pressure cylinders must be labeled with its test pressure. Not working pressure, but the extreme limit of over-pressurizing the cylinder. Think back to the era when the NFPA required that fire hose be stenciled with its test pressure. The practice was abandoned because too many firefighters ended up pleading that, darn it, that lousy hose ruptured a long time before reaching full pressure. "It says 600 psi right there on the hose, Chief!" Absentmindedly bursting a fire hose is one thing. Accidently pressurizing an airpack cylinder to its extreme limit can prove fatal.
Instead of relying on spring-loaded relief valves,
most airpack cylinders are equipped with burst disks. These prevent the
cylinder from violently rupturing while strapped to a firefighter's back.
Situations where these disks are activated are rare, but it is still an
important safety device. The DOT's one-size-fits-all rule change would require
that the pressure needed to trigger the burst disk be increased. The idea is to
reduce the chance of accidental release of proven (or unproven) toxins into the
environment. Granted, high pressure cylinders are used to store hazardous
materials. But, in the context of SCBA, increasing the disk activation pressure
makes as much sense as selling toothpaste in spray bottles. It negates an
important safety feature and clearly puts the firefighter at increased
risk.
Unlike the recent controversy involving aluminized fire gear,
firefighters still have time to get ahead of the curve on this issue. The
comment period on this new rule was originally to end in May. It has since been
extended until Sept. 30, 1999. To voice your opinion on this issue, call Cheryl
Freeman with the DOT at (202) 366-8553 or (202) 366-4545. Industrial Fire World
has already widely circulated this information via fax and e-mail. The response
has been overwhelmingly negative regarding the new rule.
As a wise man
once said, the greatest lie ever told is any statement that includes the words
"I'm from the government. I'm here to help." In this case, it is obvious that
too little thought went into whether a problem truly exists and the best way to
deal with it if it does.
Reprinted with permission