Preventing Corrosion in Concrete Coated Pipework
Presserv UK has been granted an ongoing preservation project for the protection of spare pipe spools relating to the Interconnector pipeline. These are 40” pipes regarded as critical spares and can be transferred anywhere on the 235 km length of the pipeline that runs below the North Sea due to leaks or mechanical damages. These spare pipe spools are concrete coated pipework and stored in Peterhead, Scotland.
All spares for natural gas pipelines are even more important today as in many cases production lead times for such critical items have increased dramatically. Also, stability to European energy markets and infrastructure are at risk, leading to high price volatility. Critical spares must be kept in a state of readiness, as any disruptions to existing energy infrastructure can cause additional volatility to energy markets.
It is essential that all pipeline critical spares for this natural gas pipeline are adequately stored and preserved due to the salt laden air and humidity in its stored environment. If left unattended these spare pipes would corrode within 2-3 years, leading to possible delays, shutdowns, or worse. Preventing corrosion in concrete coated pipework is of high importance and it’s easy to understand why.
In order to take a better look at preventing corrosion in concrete coated pipework, let’s take a deep dive into what concrete coated pipework is, what it is used for and finally, our preferred method for preventing corrosion in concrete coated pipework.
What is concrete coated pipework?
A concrete coated pipe is a steel pipe set into concrete. They come in different dimensions such as weight, thickness, density or diameter.
What is it used for?
These types of pipes are normally used in a sub-sea environment as the addition of concrete ensures they have negative buoyancy, causing the pipe to sink because its weight happens to be greater than the buoyant force. These pipes are therefor protected from anchoring, fishing, dredging and other activities.
What causes corrosion on concrete coated pipework?
Corrosion on concrete coated pipework is caused by exposure to air and moisture in the atmosphere. Without preventative measures, all concrete coated pipework and spares will corrode. As the spares for this project are stored close to the sea, salt in air acts as an accelerator to the corrosion process.
How can corrosion on concrete coated pipework be avoided?
Preventing corrosion on concrete coated pipework is normally accomplished using:
- cathodic protection and/or
- anti-corrosion coatings, such as epoxy paints
How can VpCI® Technology Prevent Corrosion in Stored Concrete Coated Pipework?
Internal corrosion in stored pipe spools is commonplace due to the temperature differential between the inside and the outside of the pipe, resulting in humidity and the formation of water in the pipe internals.
By fogging in Cortec VpCI® -609 Corrosion Inhibiting Powder to the internals of the pipe spools, one can eliminate corrosion in the pipe, even where there is standing water. This works by creating a molecular layer of VpCI® that is attracted to the steel on the internal of the pipe, creating a barrier that blocks oxygen and electrolytes from the substrate, thus breaking the corrosion cycle.
This method of pipework protection has been in place for over 30 years with more than 3000km of pipe spools protected across the globe using VpCI® powder fogged into the internals.
Every year we visit these large concrete coated pipes and protect them against any degradation or corrosion using Cortec VpCI® powder which is fogged internally and a wax coating on the externals where there is exposed steel.
Interested in learning more about our preservation and corrosion protection products and services? Contact us at firstname.lastname@example.org for more information.
Click below to learn more about preventing corrosion in internal cavities, voids, and interior spaces.