Flawless performance’ by contracting team as one of world’s largest regenerator
heads is removed.
Specialist engineering company for the oil and gas industry, Destec
Engineering Limited, has received warm praise for the way in which it conducted
technical operations when carrying out a regenerator and vessel head removal at
a UK-based oil refinery.
In a letter to Destec Engineering, one of the refinery’s
senior managers complimented Destec on its commitment to safety during the operation
and went on to describe the engineering company’s performance as ‘flawless’.
The
vessel was the 13th regenerator head removal carried out by Destec; and at 17m diameter
and 125 mm wall thickness, the largest it has undertaken so far and one of the largest
ever carried out.
Lincolnshire, UK-based Destec is a pioneer of the dry cutting
method for the removal of regenerator heads. The company carried out a world’s first
when, in 1996, it performed preliminary cutting to remove the regenerator head at
Mobil’s Coryton Refinery, 25 days in advance of ‘Day 1’ of the planned turnaround
start date, allowing the head to be lifted on mechanical ‘Day 2.’
The dry cutting
operation is carried out using portable milling or grinding equipment running on
two circumferential, parallel rails, fixed either side of the cut line. The method
is relatively quick, with very little post operative cleaning - unlike water jet
cutting, which can take as long as 10 days to ‘mop-up’. Thus, the method effectively
reduces overall plant down time and is very environmentally friendly.
Regarding
the latest project, preliminary contact was made by Destec as long ago as 2002,
when the dry cutting system and its advantages were outlined to the refinery’s management
team. This initial visit was not followed up until October 2004, when Destec’s engineers
were invited on-site to explain and discuss the dry cutting technique further, and
view the actual vessel.
In December 2004, senior engineers and operations’ personnel
from the refinery visited Destec’s headquarters near Lincoln, UK, and witnessed
a dry cutting demonstration on a section of a 9m diameter shell; the section forming
part of a permanent machine testing rig used for continual development of the technique.
Refinements followed and some months later, in 2005, Destec arranged for the Health
& Safety Executive to visit a ‘live’ site to view a cutting operation very similar
to the proposed new project. Destec passed this inspection with ‘flying colours’.
Throughout the rest of 2005 and early 2006, continuing minor developments were discussed
and incorporated to further tailor the technique to the refinery’s specific requirements.
Two months ahead of the turnaround, planned for 1 October 2006, work started on
installing the guide rails, followed by mounting and testing of the cutting machinery
itself, to ensure everything would go smoothly when ‘Day 1’ of the project finally
arrived.
Three days before ‘Day1’ of the turnaround, the initial circumferential
cut was commenced with the system still fully operational and at full pressure.
Destec engineers worked along the cut line to a 3mm depth, which is well within
the corrosion allowance and only possible because the technique does not penetrate
the vessel until late in the process.
When ‘Day 1’ arrived and the system was shut
down, final cutting of the vessel head and cutting of the refractory took place
- along with weld preparation in anticipation of fitting the replacement head. These
operations took two days to complete. The 630 tonne head was successfully lifted
and replaced a few days later.
Destec’s Sales and Marketing Manager, Alistair Chadwick,
comments: “Our latest regenerator and vessel head removal went very smoothly and
we are especially proud as this, we believe, is the largest diameter vessel replacement
ever undertaken. Destec is continually developing its techniques and equipment for
this specialist task and is readily available to conduct operations anywhere in
the world. Indeed, the growing number of satisfied customers who have benefited
from this technique is already in double figures and extends from the UK and Europe
right through the Middle East.
Destec Engineering Press Release
Serial Number: des2135
| Release Date: 10 April 2007
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