eastham oil refinery, uk. all photos: dan mobbs022-29)mobbs8-14_13th.pdf · susceptible to...
TRANSCRIPT
astham Refinery Limited is
a company owned 50
percent by Shell U.K.
Limited and 50 percent by
AB Nynas Limited. It oper-
ates a distillation unit established in
1966 and designed to run on heavy
naphthenic crude. In 1989 the unit was
expanded to provide a capacity of 1.2
million tonnes per year.
Assistant editor of JPCL Europe, Dan
Mobbs interviewed engineering man-
ager Andy Smith to find out how coat-
ing maintenance is handled at
Eastham Oil Refinery in Cheshire’s
Ellesmere Port, England.
Dan Mobbs: How do you begin
planning a maintenance-painting
program for a refinery?
Andy Smith: We try and paint as
much as the budget allows. We have
started a program where we allocate x-
22 JPCL Annual Bonus Issue / August 2014 / paintsquare.com
By Dan Mobbs
COATING MAINTENANCE AT AN OIL REFINERYamount each year to be utilized on
maintenance of either pipelines or
tanks. We inspect the plant to deter-
mine what the main problems are that
need to be addressed. We don’t allocate
one piece of plant every year and look
at just that.
For instance when we do a tank out-
age, and we take about five tanks out
each year to do some major repair work
or checks, we would paint the tank only
if there were any obvious pipes or sup-
ports or degradation concerns. But we
don’t say every five years, “We’re going
to go around and paint again.”
DM: You’re currently undertaking a
program to move pipe supports and
use an engineering wrap to extend
service life. What is the progress of
this?
AS: It’s a requirement by the Health and
Safety Executive [HSE, UK] to establish
more in-depth written schemes and pro-
cedures for examination of every piece of
plant. Basically some of our dock lines sit
directly on supports without shoes
attached, which can cause problems.
These lines can be in good or satisfactory
condition until they reach the support,
where you can find more localized wear
due to corrosion and erosion.
In the past, if we found issues on
these lines, we would have to cut the
Annual Bonus Issue
East
ham
Oil
Refin
ery,
UK.
All
phot
os: D
an M
obbs
24 JPCL Annual Bonus Issue / August 2014 / paintsquare.com
corroded pipe out and put a spool piece
in. This is a big issue for us because
we’ve got an 1,800-metre line down to
the QE2 docks where we load and
unload material from tankers. It’s not a
piggable line, so we have to empty the
line of something like 150 tonnes of
product and then clean the line before
we can weld. This can create problems
on the docks, as ships are coming and
going and we have to stop hot work. I
discovered, however, a company in
Aberdeen that has a composite-wrap
repair material that, depending upon the
amount of work needed on the line, can
give between 15 and 20 years warranty.
They also take responsibility for the life
of the line, and they’ve established this
with the HSE.
What I decided to do was cut away
the old support, then put in a new sup-
port and shoe up the pipe to provide a
better support about a metre further
along the line. This exposed where the
corrosion on these dock lines was. We
checked and double checked that the
results we got from the inspection were
indicative of what you’d get from an
ultrasonic test, which they were, and we
found 11 areas that had a problem with
corrosion due to a loss of wall thickness.
The company came in and did the
wraps on the dock lines, and we made
significant savings in terms of the repairs
against the spool maintenance. This
enabled the API 570-qualified inspector
to upgrade his original report regarding
the pipeline’s life expectancy.
DM: Many refineries of a certain
age suffer with dissimilar metal
corrosion. Is this something affect-
ing your facility? And if so, how do
you manage it?
AS: This plant was built 40 to 50 years
ago and was constructed with a short-
term view that it wasn’t going to be
here that long. They put stainless-steel
pipes in a lot of areas, but then the
flanges were carbon steel. That’s the
problem I’ve got now — carbon steel
flanges on stainless lines.
Our plant runs at such a high tempera-
ture that you can’t do inspection apart
from during shutdown, which we do for
four weeks in January. During the last two
shutdowns, the whole of the naphtha line
through the plant and the entire light gas
oil (LGO) line were inspected, as they’re
the two critical lines. We have isometric
drawings for the whole line highlighting
every single flange, valve and drain point;
which the inspector uses in the examina-
tion. It doesn’t take long to get the inspec-
tor’s report and photos back, so if there’s
a major concern, we order a repair and go
stainless-to-stainless.
There were no significant findings on
the LGO line. One flange was risk-
assessed and deemed it could wait until
the next shutdown. Over the next five
years, every single pipeline in this plant
will be checked and inspected. Any area
of major concern will be repaired and
areas of minor concern will be checked
visually on an annual basis to assess
degradation.
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InternationalPaint in Quark_Layout 1 7/23/14 2:59 PM Page 1
DM: Fitness-for-purpose studies on
the on-site storage tanks are cur-
rently being undertaken. Tell me
about that.
AS: We inspect tanks to EEMUA 159
[Above-ground storage tanks – a guide to
inspection, maintenance and repair pub-
lished by the Engineering Equipment &
Materials Users’ Association] which is the
specification put together a few years ago
combining both American Petroleum
Institute and British standards. We’ve car-
ried out about 50 tank inspections in 11
years, because when I came here I was-
n’t convinced about the quality of the
existing reports, so we put in an inspec-
tion regime.
Actually, this year we are coming to the
end of inspecting every single tank, but
all the inspections we are doing now,
including on pipes, are remaining-life
processes. The inspectors will calculate a
remaining life based on corrosion aspects
at the plant, and from that we can devel-
op what the inspection criteria will be. So
one tank on our log might be six years
until the next inspection and one might
be 15, which is very different from the
old days, when we would say, “It’s a
crude tank; we’ll check it every 10 years.”
Everything is now dependent upon
inspection criteria, and that’s what has
changed really in the last two years.
We’ve invested a considerable sum
over the last 10 years on tanks, modifi-
cations, and repairs. For example, we
started using a new thermal-insulating,
two- to three-mm-thick coating that
takes away the requirement for insula-
tion, on the roofs of a lot of our bitu-
men and distillate tanks.
Another example is the refurbishing of
two old tanks, situated on the banks of
the River Mersey, that store crude oil at
about 70 C. Insulation is damaged by
wind and water, which can cause huge
corrosion problems. We’ve stripped the
insulation off them already, and we’ll be
shot-blasting them clean, then using the
insulated coating, which is much cheap-
er than insulating and we can get a
good aesthetic finish.
DM: Risk-based inspections, site-
wide surveys of the paint, and
recording the condition of each
asset to meet HSE requirements
can be a major undertaking. How is
this handled at Eastham?
Everything we do on site is very
detailed and takes a lot of time to pro-
duce the necessary documents — as
well as a lot of investment. The para-
meters are continually changing.
In terms of engineering and mainte-
nance, it’s all about making everything
fit for purpose, and the only way you
can do that is identify — as we do —
the degradation mechanisms on each
piece of equipment. For instance, at
certain temperatures, erosion or abra-
sion might be occurring on some of
the lines. At higher temperatures it
could be naphthenic corrosion or sul-
phidation, so the first thing we have
to do is identify where the plant could
fail.
We identify the degradation mecha-
nism of each line, mark this on the iso-
metric drawings, and tag up and num-
ber every valve and flange. We then
inspect on the basis of the different
corrosion mechanisms, which means
doing different kinds of inspection.
One of the major jobs I’m tied up
with is going to take considerable time
from start to finish. The naphtha line
has been broken down into four areas.
The inspector has a written scheme of
examination for that piece of plant,
which tells him the drawing number,
inspection frequency, where the line is,
what it’s made of, temperatures, pres-
sures, what the required inspection
area is and what type of inspection
needs to be done. It’s a lengthy task.
We have completed the degradation
analyses, all the procedures have been
redone, and the written schemes of
examination are ongoing for a number
of plant items. We have time constraints
on completing the inspections during
shutdown, simply because of the tem-
peratures of the line. We simply can’t do
inspections all 52 weeks of the year.
26 JPCL Annual Bonus Issue / August 2014 / paintsquare.com
Annual Bonus Issue
susceptible to naphthenic corrosion
and sulphidation. We still have a lot of
other carbon steel that we’re repeatedly
measuring and monitoring, and if we
find a problem piece then we’ll cut it
out and replace it. That is principally
our view: over a period of time, most
pieces of plant and equipment will be
changed to stainless steel, but again
we’re not going to go on a knee-jerk
reaction and change everything for the
sake of it, as this new inspection criteria
will identify when it’s becoming critical.
We’ll know that it’s going to last for
three to four years, for example, and
then we can plan replacements well in
advance. Our procedure now is to
inspect, assess risk, and then determine
when we will review, repair, or replace.
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DM: What would you say the most
critical parts of the refinery are in
terms of corrosion problems and
how are they protected?
AS: The most critical pipelines are
those above 200 C and less than 330
C, because that’s almost the breeding
ground for naphthenic acid corrosion
(caused by oxidation of naphtha) and
sulphidation, which are the higher-end
degradation mechanisms. With naph-
thenic corrosion you could have a 200-
metre piece of line that looks perfect,
but in fact you could have a wormhole
straight through the line.
We’re replacing a lot of the original
carbon steel with stainless as we go, as
the basic 316 stainless grade is less
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We changed a significant amount of
heat exchangers, fin fans, and pipes to
stainless steel over the last 12 years.
When I first came here, people were
doing inspections ad nauseam. Now
we’ve expanded the inspection to five
or six techniques, all specific to what-
ever piece of plant we’re doing.
Because the inspections are more
detailed, we are actually reducing the
rate of inspections.
There are three major heating units
here at Eastham, which were always
difficult and expensive to inspect.
Ultrasonic testing was used to carry
out the inspections, which gave a lim-
ited amount of results, but then we
came across a company from The
Netherlands that carried out inspec-
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paintsquare.com / August 2014 / JPCL Annual Bonus Issue 29
tions by intelligent pig and we have
used this method for the last two
years. Not only did it give us 100-per-
cent inspection of the tubes, it also
cleared any potential fouling that could
have been building up. The cost for
carrying out this inspection has proved
economical, not only because it gives
us a full picture of the pipework, but
now we don’t have to go in the heater
every 12 months; it’s now every five
years, so the savings we’ve made are
huge.
There are a lot of inspections to be
carried out, and because we’re now
doing it right, it gives us the confidence
to expand the inspection regimes.
Although the initial inspection cost is
high, long term it’s more economical.
DM: What are the specifications for
the surface preparation and coat-
ing of the different areas?
AS: I don’t specify any surface prepara-
tion, but leave it to the coating people
to prepare accordingly for the coating
they are applying. When we’re doing a
tank with the aforementioned thermal-
insulating coating for example, they
might water-wash and bristle brush
and give me a 10-year guarantee. Even
if it were a specialist coating, I would
still leave it to them and wouldn’t
specify what they need to do. All I’m
interested in is how much it’s costing
and what the guarantee is. That’s their
criteria. JPCL