RiskUKSeptember2017

Gaseous Fixed Firefighting Systems:
Design, Selection and Installation
The whole process has
taken six months and
significant input from
a range of experts, but
the Fire Industry
Association has now
published a new
guidance document
designed to demystify
the standards
surrounding the
design, selection and
installation of gaseous
fixed firefighting
system pipework. Alan
Elder and Robert
Thilthorpe address the
all-important points to
note for fire safety
professionals
Alan Elder: Chairman of the Fire
Industry Association’s Working
Group on Gases
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For those readers of Risk UK not familiar
with the technology, a gaseous fixed
firefighting system is one that does what it
says on the tin. In short, it uses a gas-based
agent to put out a fire either by displacing
some of the oxygen in the room to suffocate the
blaze or by removing heat. The method is
dependent on the type of agent used.
A fire protection system like this is commonly
employed in facilities such as Data Centres,
where delicate and high-risk computer
equipment could suffer damage from other
extinguishing media, such as water, foam or
powder. The solution design itself ensures that
the gas system extinguishes the fire both
quickly and cleanly and without damaging any
sensitive and expensive equipment.
After all, in a space such as a Data Centre,
the loss of valuable data would come at a
tremendous cost to a business, while the
knock-on effect to other systems and
businesses reliant on that data further down
the line would be hugely detrimental. Not to
mention the actual physical cost of losing the
hardware itself and having to replace it.
Therefore, protection of that facility from fire is
imperative when it comes to reducing the risk
of costly business interruption.
In almost all gaseous firefighting
installations, the agent is delivered to the
protected hazard through a network of
pipework. Installing the pipework presents a
number of challenges. Ensuring that the
pipework is correctly designed and specified is
important to avoid issues that could affect the
safety and effectiveness of the system. Pipe
threads that don’t match, improper seals
between pipework carrying the gas, corrosion
and using pipes of the wrong size or wall
thickness could all lead to the overall detriment
of the system.
Ultimately, the key points to observe here are
knowing what problems there could be and
also how to avoid these common pitfalls.
Skills and experience
The supply of gaseous fixed firefighting
systems requires a number of skills, experience
and specific knowledge of the equipment,
design codes and the hazards associated with
handling high pressure gases. Incorrect
handling of gas containers can be particularly
hazardous as they hold gases stored under
pressure, as do the pipes that allow the flow of
the gas to the hazard area. Individuals need to
understand how to install gaseous systems
such that the system is not only operational,
but also safe.
In a previous document, the FIA addressed
the issue of the safe handling of pressurised
container assemblies used in fixed firefighting
systems. The new guidance document covers in
some detail the pipework used in gaseous fixed
firefighting systems, duly identifying the
possibility that ‘should there be a major failure
of any pipe and/or fitting, a number of hazards
may arise, including projectiles, the release of
toxic agents (for example CO 2 ) or asphyxiants
in confined spaces, pressure effects/structural
damage and the consequential compromise of
extinguishing capability’.
Safety is the major issue that has inspired
the Fire Industry Association’s (FIA) Working
Group on Gases to create a series of useful,
freely downloadable documents, each designed
to explain the key safety concerns for those
working with, handling and/or installing these
systems. The latest in this series of documents,
the FIA’s Guidance Note on ‘Pipework for
Gaseous Fixed Firefighting Systems’, contains
an expanse of information based on the
technical knowhow of the experts who
prepared it and includes handy referral charts
and formulas for working out which pipes
should be selected.
There are a number of concerns in the
industry, especially when it comes to pipework.
One of the foremost of those concerns is that
people can mix up British and American
Standards. It can happen accidentally as there
are standards for pipes in the UK that are
different to the ones in the States.
People don’t necessarily realise that pipe
fittings manufactured to British Standards may
not be compatible with fittings manufactured to
American Standards. It’s entirely possible that
one installer may be familiar with American
Standards and another with British Standards.
If components are mixed on the same system,
then there could be some compatibility issues
between the different types of fittings which
may then lead to a decrease in the integrity of
the system as a whole.
Pipe selection is one of the guidance areas
covered by the new FIA document. Choosing the
wrong pipe or making a mistake in calculating