Once a pipeline has been assembled and hydrotested, Zerust has a unique application that can protect pipelines from internal corrosion until the pipeline is commissioned. This process can eliminate the need for dry air or a Nitrogen purge.

Zerust’s unique blend of Zerion Inhibitors is first mixed with water. The inhibitor slurry is then pumped between two pigs. The lead pig is typically a wiper pig and the trailing pig is a filming pig which will leave a thin layer of the Vapor Corrosion Inhibitor (VCI) slurry on the surface of the pipeline.

Soluble Corrosion Inhibitors or SCI in the slurry will neutralize contaminants on the steel surface upon contact. Volatile Corrosion Inhibitors will evolve from the slurry to provide continuing protection to the entire internal surface. Compressed air is typically used to push the pigs and neither dried air or Nitrogen is required at any point in the process. The surface area of the pipe is in contact with the slurry which then sheds to the 6 o’clock position of the pipe. The surface comes into direct contact with the SCI’s in the chemistry. The inhibitors will neutralize moisture, and acidic species.

Vapor molecules volatize into the annulus of the pipe and adsorb onto the steel surface. As the pigs move, the inhibitor slurry is deposited as a thin film on the internal surfaces of the pipeline and the SCI is in direct contact with the entire metal surface area of the pipe interior. VCI molecules are released that protect the bare metal surfaces. The inhibitor molecules fill the pipeline as well as any gaps due to valves, ports and instrumentation. Excess slurry drains to the bottom of the pipeline. Corrosion inhibitor particles remain even when water flows to low points in the pipe, still releasing VCI molecules. In the event of any water ingress, the inhibitor will neutralize corrosive contaminants.

Zerion FVS has been shown to be beneficial in mitigating bacteria which may have been present in the hydrotest water. Long lengths of piggable pipelines can be protected using this method. Zerust has successfully implemented this solution on significant pipeline lengths.

Do you have a pipeline in the pre-construction or pre-commissioning stage for which you need anti-corrosion solutions?

Contact us today for your corrosion management needs.