TECHNO Assistance, the On-Site Waterjet Cutting spin-off of Waterjet Technology (Pty) Ltd , recently completed work on Chevron South Africa’s 2010 turnaround at their Cape Town refinery. This was a major undertaking, with much of the plant being shutdown and refurbished.

Techno Assistance’s particular emphasis and input was on the FCCU (Fluid Catalytic Cracking Unit) on Plant 63, where they performed key roles in hydro cutting, on site machining and the supply of various specialised components.

The hydro cutting, says managing director Simon Baschiera, consisted mostly of pipe cutting ranging from 600mm to 900mm in diameter, all with refractory (heat resisting cement) on the inside of these lines. They also performed various on site machining functions with flange face machining and gramophone finishes on flanges ranging from 1" to 10".

The last but most important achievement was that of implementing a new dry cutting technology to remove the dome (top of tank) off a large diameter vessel. This was performed on the regenerator (large boiler tank) measuring 6.1 meters in diameter.

“This dry cutting technology was adapted and engineered specifically for this project, and is a first, as far as we know, in South Africa,” says Baschiera.

The major reason for this ‘dry cut’ was to negate water ingestion inside the regenerator, which could have caused considerable delay in the cleaning of the resulting slop. The dry cut therefore made it possible to enter and work inside the regenerator immediately after the dome was lifted.

Further benefits of cutting the dome off in this manner was that the dome could be lifted off with all its internal attachments (cyclones), improving accessibility to parts under repair.

The process went well in the circumstances, he says, and was achieved within the planned time and constraints. The slit or cut included an angle (weld bevel or prep) further reducing the downtime of the FCCU and scheduled work.

Techno was also awarded a prestigious Safety award for best Small to Medium Sub-Contractor on site, by Chevrons world class safety team.