Over the course of several years, a steel fabricator in Scunthorpe, UK, has saved millions of pounds by deploying a series of polymeric repair and protection systems, including epoxy repair mortars and stainless steel protective coatings, on their gas pipeline.
Severe Pitting and Corrosion Damage
In 2016, after 45 years of service, the gas main was exhibiting severe pitting and corrosion damage. This was taking place at the four o’clock and eight o’clock positions on the 2.7-m-diameter pipeline, where a waterline between liquid and gas forms.
Having previously opted to replace the steel pipes, the client was looking for an alternative solution to this, bypassing the costly fees that replacement can incur. For each meter of pipeline replaced, the client paid £8,000. This meant that to replace the 90-m section, the cost was £720,000.
Short Time-Frame Allocated for Pipe Repairs
Independent Consultant, David Keen, said, “The whole site is completely reliant on this pipeline. As such, the site allocate just 14 days for its annual outage. This short timescale seriously limits the amount of maintenance work that can be carried out.”
He continued, “In previous years, contractors were only able to replace small amounts of pipeline within this timescale. It was clear that this method of pipe maintenance had serious limitations, not to mention the significant amount of capital required to completely replace the damaged areas.”
Specification of Repair Mortars and Stainless Steel Protective Coatings
Following an inspection carried out by Belzona, international manufacturers of polymeric repair composites and industrial protective coatings, a series of systems were specified. These included: Belzona 1151 (Smoothing Metal), Belzona 4151 (Magma-Quartz Resin), Belzona 4154 (Bulkfill Resin) and Belzona 5811 (Immersion Grade).
Not only could these systems offer outstanding repair and protection, but the savings the client would make by avoiding the need to replace the assets were huge – approximately 16 million pounds.
In addition, as the polymeric systems can be applied without the use of hot work, this further ensures that downtime is kept to an absolute minimum. Thus allowing the steelworks to make further savings by investing in the composite repair materials and industrial coatings.
Simple Application Procedure
First, the area was cleared of residue, grit-blasted, and then 150 mm x 150 mm plates were bonded over any holed areas using Belzona 1151. Heavily pitted areas were filled with Belzona 4151 or Belzona 4154 combined with kiln-dried sand.
Next, in order to provide complete corrosion protection for the heavily pitted and holed areas, two coats of Belzona 5811 (Immersion Grade) were applied at double the thickness to the substrate, giving a total thickness of 1000μm.
Contractor Wins National Award with Polymer Technology
Giving an overview of the scale of the project, David Keen said, “By using the polymer systems, this enabled the client to protect much larger sections of the pipeline than was previously possible. Usually, this amounted to 350m each year.”
He added, “However, in 2018 they protected a phenomenal 750-m stretch of the pipeline in just nine days. In fact, this application won the Contractor a National Award for the speed in which the repair was carried out, as well as the huge savings it allowed the client to make.”
Over 2 km of Epoxy Protection By 2022
Starting in 2016 through to 2020, Belzona materials have been deployed across the pipeline to combat the widespread corrosion. This totals 1,300 m, with a further 730 m of repairs scheduled for 2021 and 2022.
This repeat business is testament to the polymeric systems’ excellent corrosion protection characteristics, along with quick and easy application method. The combination of which will save the client millions of pounds by the end of 2022.
