Replacement corroded bolts | Hot Bolt Clamp & Rope Access



Major operator


Central north sea


Upstream oil and gas

Associated capabilities


The Client identified corroded bolts on 29 four-bolt flanges on the fire water ring main of its floating production platform. As the safety critical system cannot be isolated, depressurized and drained, even during shutdowns, the flange bolting could not be changed out using conventional hot bolting techniques.

The bolting was in poor condition due to the salt water atmosphere which caused severe corrosion of unprotected carbon steel components. The height and position of the flanges meant that scaffolding could not be easily constructed for access.


Stork’s innovative Hot Bolt Clamp technique and rope access solutions allowed the corroded bolts to be removed and replaced without disruption to the safety system. A number of flanges were located under the helideck and careful planning was required with the platform’s heli-admin team to avoid sim ops with helicopter operations. The project was staggered to allow the Hot Bolt Clamp team to manage the deck level flanges first, then the rope access team mobilized to work on the difficult to reach flanges.


Quicker, quality delivery
Using the Hot Bolt Clamp in conjunction with rope access reduced labor costs by six days, completing the scope ahead of the scheduled timeframe and well within budget

Safe and secure operations
The work was delivered without interruption to plant operations, zero safety incidents and no harm to the environment

Plant integrity restored
Plant integrity was fully restored to 'as new' condition depressurizing or isolating the plant, which is time-consuming and costly.

“It was a good scope with positive feedback from the platform, an excellent option for those always hard to do joints due to isolation restrictions etc.”
Client engineering coordinator

Project details

Projetc name: Removal and replacement of corroded bolts on fire water ring main

Services: Hot bolt camp and multi-disciplines rope access

Date: 2015