NFPA Journal - Spring 2022 - 59

In Compliance
microbiologically influenced corrosion,
where small organisms create a biofilm
that corrodes the metal, and galvanic
corrosion, where dissimilar metals
react with one another and result in
corrosion.
Regardless of the type, corrosion can
eat away at pipes and other sprinkler
components, reducing pipe smoothness
and creating pinhole leaks that
can result in water damage and reduce
the effectiveness of the sprinkler
system. Enough corrosion can cause the
entire sprinkler system to fail, which
can result in property damage, loss of
productivity, major expense, and even
personal injury.
There are a number of ways to
manage and prevent corrosion, many
of which are required by NFPA 13 when
sprinklers are installed in corrosive
environments. One method involves the
use of nitrogen generators. Since corrosion
occurs when metal reacts with
oxygen, removing the oxygen from the
sprinkler system is an effective way to
combat corrosion. This can be done for
dry and pre-action systems by utilizing
a nitrogen generator or nitrogen cylinders
to fill the sprinkler piping with
nitrogen instead of air.
A new provision of the 2022 edition
of NFPA 13 addresses the use of a nitrogen
generator in conjunction with dry
or pre-action systems and takes a new
approach to the hydraulic requirements
of those systems. An important
component in those calculations is the
" C factor, " which is the relative roughness
of a pipe's interior, typically caused
by corrosion, impacting water flow
through the system. The higher the
number, the smoother the inside of the
pipe; piping with a C factor of 150 is
much smoother than piping with a C
factor of 100, meaning water will flow
faster and more efficiently through pipe
with the higher C factor. In the previous
edition of NFPA 13, the required C
factor when using nitrogen with black
steel or galvanized steel pipe was 100,
the assumption being that corrosion
would occur over time and that systems
would need to be built to provide
enough pressure to overcome the added
friction and turbulence inside the pipes.
In the new edition of the standard,
the C factor when using nitrogen
generators along with black steel or
galvanized steel piping has been raised
to 120, which has important ramifications
for designers, installers, and
building owners. By assuming there
will be less corrosion present in the
pipes, it may be possible to build new
sprinkler systems with reduced pressure
demands; fire pumps may not be
necessary, smaller pipes can be considered,
and other cost-saving steps may
be feasible as well.
A few additional requirements
were added to take advantage of this
increased C factor. The nitrogen generator
must be permanently installed,
it must be listed, it must be installed
per the manufacturer's instructions,
and it needs to be able to supply and
maintain a 98 percent nitrogen concentration
at a leakage rate of 1.5 psi (0.1
bar) per hour. The generator also needs
to have a means of verifying the nitrogen
concentration, and it needs to be
maintained in accordance with NFPA
25, Standard for the Inspection, Testing,
and Maintenance of Water-Based Fire
Protection Systems.
These changes were made largely as
a result of several independent studies
that have shown nitrogen to be
a highly effective means of reducing
corrosion in sprinkler systems. By
settling on a new C factor of 120, the
NFPA 13 technical committee built
in a margin of safety that assumed at
least a bit of expected corrosion, rather
than assigning a higher C factor typically
associated with new piping. It is
important to note that these changes
only apply to systems utilizing nitrogen
generators rather than tanks of
nitrogen.
We want fire protection systems
to be reliable, affordable, effective,
and long-lasting. With these changes
to NFPA 13, designers can now take
advantage of the hydraulic benefits
provided by a dry or pre-action system
with a nitrogen generator.
Brian O'Connor is technical lead, Fire Protection
Engineering, at NFPA. NFPA members and AHJs can
use the Technical Questions tab to post queries on
NFPA 13 at nfpa.org/13. To follow the progress on the
upcoming edition of the code, visit nfpa.org/13next.
NFPA 70 + 70E
Electrical Safety
Communicating
electrical safety
to the world
By Corey Hannahs
L
ate last year, NFPA
added a Spanishlanguage
translation of
the 2021 edition of
NFPA 70E®
, Standard
for Electrical Safety in the Workplace®
to the NFPA LiNKTM
digital platform.
This addition represents a significant
step toward improving electrical
safety for more than 550 million
Spanish-speaking people around the
world. In the United States alone,
about 19 percent of the construction
workforce is of Hispanic or Latinx
ethnicity. In many cases, these workers
are not bilingual and are only able
to communicate in Spanish. Being
able to convey electrical safety
processes and procedures on jobsites
to individuals performing electrical
work, as well as other tradespeople,
is of the utmost importance
and is a critical part of the NFPA
safety mission.
Electrical safety is a tool that every
electrician needs in their arsenal.
Without it, it isn't a matter of if you
will be injured-the question is when.
At the highest level of electrical safety,
NFPA 70E is both trained and implemented
effectively. Communication
is a critical component to being able
to achieve both. Electricity does not
differentiate based on language, and
electrical safety can't, either.
The addition of the Spanishlanguage
version of NFPA 70E is an
important update to NFPA LiNK.
The tool delivers NFPA codes and
standards, expert commentary,
and supporting content that allows
users to easily navigate and understand
code requirements based on
real-life situations. The addition of
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NFPA Journal - Spring 2022

Table of Contents for the Digital Edition of NFPA Journal - Spring 2022
