UK global bolting and engineering technology firm Hydratight Ltd reports that it has saved chemicals and manufacturing company Huntsman money and time by using a computer-controlled tool to repair, in-situ, a large reactor-vessel flange.
Hydratight was performing bolt tensioning and ultrasonic measurements on a reactor at the Huntsman facility on Jurong Island, Singapore. Testing identified an issue with 90-mm (3.5-in) studs on a special 500-mm (20-in) flange on the reactor. The bolt failed to reach its required 40 000 psi stress level because of damaged threads.
Huntsman engineers confirmed earlier findings through further pressure testing that was performed on the reactor. Hydratight engineers were asked to assess the way in which the repair could be carried out. A proposal was made to use the company’s GeniSYS 220CNC - a 3D mobile milling machine - to bore out the damaged threads to 102 mm (4 in), then use reducers to restore the threads to 90 mm (3.5 in).
“Though simple in theory, such a job could have been very difficult in practice,” commented Hydratight’s Mark Foggin.
“The repair had to be extremely accurate - which is not really possible using conventional equipment, especially under site conditions and on such large bores. To get it wrong would have meant an even greater and more dangerous, potential for failure.”
“But we have seen the GeniSYS do some amazing work in worse circumstances in the past, so we knew we could complete the operation safely and efficiently, and meet the level of accuracy set by Huntsman.”
The machine and Hydratight specialist Rick Betteley were flown out to the plant and machined five new holes in the space of a few hours - during one shift - with the help of local colleagues and Huntsman staff. The stepped-down studs were fitted and bolt tensioned, and the repair was tested ultrasonically.
“The vessel passed all the company’s tests and is now back in full operation,” continued Foggin.
The cost of the repair was only a third of that of a new reactor - not including the massive associated costs of shutdown and replacement.
“Huntsman staff were so pleased they immediately asked us to re-cut threads on two more reactors within the next six months - saving a huge amount of money and time in the process,” added Foggin.
For further information, contact:
Hydratight Ltd, Bentley Road South, Darlaston, West Midlands WS10 8LQ, UK. Tel: +44 121 50 50 600, Fax: +44 121 50 50 800, Email: walsall@hydratight.com, Web: www.hydratight.com
Hydratight Pte Ltd, 83 Joo Koon Circle, Unit 01-03, Singapore 629109. Tel: +65 6515 4971, Fax: +65 6515 4972, Email: singapore@hydratight.com
No comments:
Post a Comment