CORROSION UNDER
INSULATION SERVICES
The costs of corrosion
for companies and
the economy can be
astronomical. According
to National Association
of Corrosion Engineers (NACE)
International: “The global cost of
corrosion is estimated to be US$ 2.5
trillion, which is equivalent to 3.4%
of the global gross domestic product
(GDP 2013).
By using available corrosion control
practices, it is estimated that savings
of between 15 and 30% of the cost
of corrosion could be realised i.e.
between US$375 and $875 billion
annually on a global basis.”
A big challenge for the food industry
is corrosion under insulation (CUI),
which occurs when halogen
compounds (compounds of chlorine,
bromine, or fluorine) become trapped
with moisture in the insulation
material, corroding even stainlesssteel
piping.
Not only is corrosion a major drain
on business finances, it also poses
a threat to health and safety, an
example of which is Ammonia
refrigeration pipework. According
to a technical bulletin issued by
WorkSafe, the uncontrolled release
of ammonia from a refrigeration
plant is a critical work health
and safety risk, which must be
managed effectively to minimise
the risk of harm. It reported that in
2017, approximately 20 ammonia
releases were notified to WorkSafe
New Zealand, highlighting the
importance of risk assessments
and implementing appropriate
control measures. In the bulletin,
they highlight two main causes of
ammonia release, one of which is
equipment failure, including corroded
pipework.
Stork, a Fluor company – described
as a leader in asset integrity solutions
– is experienced in providing CUI
inspections through a number
of non-destructive testing (NDT)
techniques and has completed
CUI inspections for a wide range of
companies across New Zealand and
Australia.
A favoured technique for CUI
inspection is Digital radiography,
a non-invasive method which can
be used for wall loss type flaws
i.e. corrosion pitting, generalised
corrosion and erosion. Coupled with
the company’s unique ‘Open Vision’
screening tool, it can complete large
quantities of pipework screening
relatively quickly without disruption
to production, saving the client both
time and money. One client, says
Stork, reported a cost saving of
between NZ $200,000 to $300,000
by not having to remove the
insulation.
In order to further mitigate the risk
of CUI resulting in an uncontrolled
release of ammonia, Stork offers
continued proactive monitoring,
finding vital information for accurate
life expectancy forecasting of the
refrigeration piping through erosion
corrosion inspection and wall
thickness monitoring.
For more information on how Stork
can assist with your CUI needs,
contact the team on 06 753 6169.
FOOD IN ENGINEERING
A corrosion survey was conducted at areas of
concern on a 4-inch line, using digital radiography
34 March 2020