3X Engineering repairs cracks on huge column in Libya

The objective of the repair, carried out at the end of December 2019 by 3X ENGINEERING (3X) and its local distributor AL MAIDA, was to reinforce 3 circumferential welds suffering from cracks, situated on a huge column. The column is a 264 inch MDEA regenerator column with acid gas and a maximum operating temperature of 90°C. The design pressure is 1 bar.

According to ISO 24.817 and 3X repair calculations, 4 composite layers of REINFORCEKiT® 4D HT+ (specifically dedicated to high temperature) were determined to reinforce the defects.

Scaffoldings and surface preparation were already managed before 3X team arrival. The surface preparation was made according to 3X requirements to get a good surface roughness and ensure a good bonding between the steel of the column and the composite of the repair. Upon arrival, 3X specialists checked the surface profile and the hygrometric conditions and cleaned the surface using acetone before starting the wrapping procedure (steps described below – the procedure is the same for the 3 welds to be reinforced).

1. F3XS1 filler was applied on the weld to smooth the shape and improve the Kevlar® tape fitting on the column.

2. R3XHT+ resin was applied on the surface to ensure the perfect impregnation of the Kevlar® tape.

3. Composite wrapping was completed using Kevlar® tape impregnated with R3XHT+ resin → 4 layers and 1270mm repair length for each defect. During the process, tape impregnation was checked on both sides to ensure the expected performance.

4. Finalization of the repair. A layer of R3XHT+ was applied all over the repair to ensure good wetting and improve the visual aspect. Reference plate was installed on each repair for traceability purpose.

Column overview with welds location

For each repair, samples of filler and resin were taken during application for quality control.

Hardness measurements were performed 3 days after job completion and concluded the good achievement of the repairs. This project was challenging because of the large column diameter and the time frame for completing the job. The column was successfully reinforced on the weakest areas and is now protected from leaking issues.