In
1976, Structural Composites Industries (SCI) was issued the first Department
of Transportation (DOT) approval for the manufacture of composite wrapped
high pressure gas cylinders, this approval was for a Chevalier®
wrapped cylinder which was used to inflate evacuation slides on the
Boeing 747. In the past 30 years, SCI has received 7 additional approvals
including approval for carbon composite cylinders in 1996.
SCI
has designed hundreds of DOT approved composite cylinders ranging in
size from 45 cu in (.74 liters) to 5450 cu in (89.3 liters) with operating
pressures of 1850 psi to 5000 psi
.
The
advantage of carbon composite cylinders is their very high strength
to weight ratio. Carbon composite cylinders are typically 10 to 20%
lighter than comparable Kevlar cylinders and 60 to 65% lighter than
comparable steel cylinders. Carbon cylinders have a minimum safety factor
of 3.4 to 1 and the typical safety factor is 3.6 - 3.7 to 1.
Commercial
Aviation is one of the largest users of carbon composite cylinders.
Composite cylinders are used to inflate evacuation slides, store oxygen
for the passengers and crew, inflate emergency floats on helicopters,
and store energy to open doors, lower flaps or the landing gear.
