Richard Atkinson discusses how gas detection methods are
evolving to meet the demands of an energy hungry world
Gas detection can be traced back
to the coal mines in the 19th
century; where canaries were
used by mineRichard Atkinson discusses how gas detection methods are
evolving to meet the demands of an energy hungry world
Gas detection can be traced back
to the coal mines in the 19th
century; where canaries were
used by miners to ensure their safety as
they descended into the bowels of the
earth. Since then, our usage of gas has
increased significantly and evolved to a
major source of energy while the spectre
of harmful gas emissions remains.
However, gas detection has benefited
from the advent of new technologies
and, thankfully from the canaries'
perspective, made them redundant.
Why be concerned about the
integrity of pipework?
Failure to check for gas leakage and
maintain outlet pipework to an adequate
standard carries significant risks which go
far beyond the commercial fall out as a
result of disruption to your gas supply.
In the modern, energy-hungry world,
gas leaks can cause numerous
commercial, environmental and health
and safety issues. Organisations can see
increased costs in a variety of ways
through a seemingly small gas leak caused
by corrosion to existing pipework.
There is the obvious impact of
increased energy usage if the leak is not
identified and repaired, leading to higher
bills. A loss of pressure due to a leak may
also cause machinery or infrastructure to
run inefficiently or suffer long term
damage leading to potential further loss
while unplanned maintenance or
replacement is carried out.
There is also the environmental impact
of over using a scarce natural resource to
consider. However, the implications with
regard to health and safety are perhaps the
most serious. As natural gas and LPG are
combustible, the failure of organisations
to detect and deal with leaks can lead to
explosions causing significant commercial
loss, casualties and even fatalities. In
some cases company directors have been
prosecuted and heavy fines imposed due
to their negligence in failing to inspect gas
outlet pipework for defects.
Tackling the issue:
There are a wide range of technologies
that can be used to detect different types
of gas leaks. Current technologies are
becoming more and more advanced. A
selection of current methods are listed
below:
Electrochemical sensors - these work
by allowing gases to diffuse through a
porous membrane to an electrode
where it is either oxidized or reduced,
the amount of current produced can
then be measured to determine the
extent of the leak. It is recommended
to use this for toxic gas applications in
environments such as refineries, gas
turbines or chemical plants.
Infrared point sensors - these use
radiation passing through a volume of
gas to detect leaks. Energy from the
radiation is absorbed as it passes
through the gas at certain wavelengths.
These are used in wastewater treatment
plants, refineries and gas turbines
where there is a potential threat of
explosion.
Ultrasonic detectors - these use
acoustic sensors to detect changes in
the background noise of the
environment. Most gas leaks occur in
the ultrasonic range of 25 kHz to 10
MHz, the sensors are able to easily
distinguish these frequencies from
background noise which occurs in the
audible range of 20 Hz to 20 kHz.
Ultrasonic gas detectors are mainly
used for outdoor environments where
weather conditions can easily dissipate
escaping gas before allowing it to reach
other gas leak detectors.
Semiconductor sensors - these detect
gas by a chemical reaction that takes
place when the gas comes in contact
with a sensor and are commonly used
to detect harmful gases such as carbon
monoxide. Because the sensor must
come in contact with the gas in order
to detect it, semiconductor sensors
work in a smaller range than infrared
point or ultrasonic detectors.
Despite the relative ease with which gas
leaks can be tackled, many organisations
fail to inspect external gas supply pipes.
These pipelines need to be treated the
same way in which you would treat a gas
burning appliance; regularly by qualified
personnel.
The IGEM (Institute of Gas
Engineering Managers) UP/2 (Inspection
& Maintenance) standard states that a full
inspection and maintenance plan should
be drawn up for all downstream gas outlet
pipework and that it should be supported
by an annual inspection and soundness
testing that is completed every five years.
Organisations have a responsibility to
their employees, shareholders and the
general public to ensure that they operate
in a safe and responsible manner.
Anyone concerned about a gas leak
should call: National Gas Emergency
Number: 0800 111 999.
Richard Atkinson is the sales and
marketing director at Fulcrum.
