"This heat exchanger is so powerful that it will never rust. But it must be sealed and withstand pressure for the next 25 years," says Head of Fabrication, John Vester Nielsen.

Intense work is being carried out in the workshop on a flange at one end of the grey colossus. Four men are busy. One is secured with a safety harness and sits on top, communicating with the others.

The heat exchanger is one of several installations that Halvorsen has been commissioned to extend the lifespan of for a customer.

– BEFORE THIS It came here to the workshop, was dismantled from the ship and sent for sandblasting. We reassemble the parts, pressure test and inspect. When our job is finished, the exchanger is sent for painting again before it is handed over to clients, Nielsen explains.

The heat exchanger comprises, among other things, 500 small tubes. These must be sealed and withstand pressure. Through thorough pressure testing of all the tubes, leaks were discovered in eight of them.

– It is impossible to insert new ones. The pipes that are not sealed are therefore plugged. In that way, they are taken out of production and no longer pose a risk, says Nielsen.

BESIDE The heat exchanger has several smaller pressure tanks and filters in a row. They have also been refurbished and are ready for another 25 years in the North Sea.

In the second part of the workshop, the following is carried out: extensive engineering work and upgrade on an eight-metre long, four-metre wide and seven-metre process module. There are over 1000 parts dismantled and reassembled.

Five men are working to secure the flanges.

The bolts are tightened.

John Vester Nielsen, Head of Fabrication, is measuring the diameter of the heat exchanger.

500 small tubes go through the exchanger. Eight of them had to be plugged.

Full concentration on top of the heat exchanger.

Several small pressure vessels and filters have had their service life extended and will be returned to the customer.