Threading the needle
In a carefully orchestrated display of engineering expertise and teamwork, our project team in Lithuania successfully transported and installed a new stabiliser column, a key milestone in the modernisation and expansion of PC ORLEN Lietuva’s Mažeikiai Refinery.
Why the new column was essential
As part of our contract with the client, we were tasked with delivering a new Residue Hydrocracking Unit (RHCU) to help increase the refinery’s processing capacity. From the outset, our experts recognised that the existing stabiliser column would not be able to accommodate the higher volumes of naphtha and diesel produced by the new unit, alongside the ongoing vacuum gas oil feed. This prompted us to build a new column designed to support the increased throughput while maintaining overall processing performance.
Height
40
metres
Diameter
3
metres
Weight
70
tonnes
24 months of planning, one solution
Delivering a piece of infrastructure of this scale is never straightforward particularly within an active, space-constrained site.
After careful assessment, our engineers concluded that moving the column in one piece would be quite challenging logistically. So, they came up with a detailed plan to split the vessel into two sections separating the pressure part from the skirt. This adjustment shortened the length by about seven metres and made it much easier to manoeuvre
Engineering ingenuity and attention to detail
With limited existing documentation on subsurface conditions and ageing infrastructure, preparations included road reinforcement works, the installation of steel plates, and construction of a new retaining wall to support the transport vehicle’s load.
Additional challenges included accommodating operational ventilation ducts, which could not be taken offline for more than eight hours and temporarily rerouting narrow cable trays carrying fibre optic cables. Design adjustments and temporary modifications enabled these essential systems to remain functional while allowing safe passage of the equipment.
Razor thin margins
Almost
0
Lateral clearance between the wheels and the edge of the concrete paving
Just
80mm
Between the top of the vessel and the control room wall
Around
100mm
Between the column and the live operational piping
It was a huge a moment of pride when the column arrived at site, and even more so when it was safely set on its foundation. The entire team, including the client and others watching on, broke into applause and hugged each other, definitely one of the highlights of my career.
The successful installation of the stabiliser column is a clear example of how our people collaborate to overcome complex engineering challenges with skill and foresight. With the unit now in place, the project moves another step closer to the completion of the broader refinery upgrade delivering long-term value for our client.