Company praised for oil refinery project

Edited by the Engineeringtalk editorial team Apr 24, 2007

A refinery senior manager has complimented Destec on its commitment to safety during a regenerator and vessel head removal

Destec Engineering has received 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 22mm 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 and Safety Executive to visit a "live" site to view a cutting operation very similar to the proposed new project.

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".