Setting new standards for epoxy coatings

During the late 1990s, the Canadian pipeline market required a new and improved high build, fast curing epoxy that could be applied to work with factory applied Fusion Bond Epoxy (FBE) coatings. The liquid epoxy needed to be capable of being applied in both summer and winter, with significant steel preheat. Moreover, the application process had to be relatively simple and require minimal training. In response to this demand, Denso North America developed Protal 7200TM – as an improvement on our existing Protal 7000TM liquid epoxy coating – to meet the said requirements.

Meeting industry demand

Protal 7200 is a two-part liquid epoxy coating that is VOC-free, 100% solids, and specially designed to complement FBE coated pipes. It is a high-build liquid coating – providing up to 70 mils (1778 microns) in a single coat – that can be applied in either the field or the shop. It cures rapidly, allowing for quick handling and backfill times; can operate at temperatures up to 95°C (203°F); and is our signature liquid coating that is the preferred choice for many of our customers to the present day.

Protal 7200 is designed to be applied using brush, roller or spray application methods. It has always been extremely important to every subsidiary operating within the Winn & Coales International Ltd. (WCI) group of companies that our customers feel confident in applying our range of corrosion prevention systems and we take great pride in training teams to the highest standard in application methods. With this ethos in mind, and to ensure proper application of our new liquid epoxy coating, a training specification was first created for the brush grade application of Protal 7200. Site training was deemed a crucial element of the specification as many applicators had no prior experience with liquid epoxy application – plus, most of the work was being undertaken on-site.

During the application training of Protal 7200, the first step was defined as ensuring proper surface preparation of the substrate was completed before any other work was started. This process began with surface cleaning, followed by abrasive blasting to produce an angular profile of 2.5 - 5.0 mils, with the abrasive blasting completed to produce a near-white finish (SSPC SP-10, NACE No. 2 or Sa 2 1/2). The substrate temperature range for the application of Protal 7200 was recognised as between 50°F (10°C) - 212°F (100°C). Before proceeding with the coating operation, the substrate temperature had to be seen to be at least 5°F (3°C) above the dew point temperature. This application specification was revised as required, and the training was based on this specification.

The market also demanded a spray grade version of Protal 7200, which could be used in plural component sprayers to mix and atomise 100% solids epoxies. However, using this version of the system required additional training and testing to ensure proper application and performance. To address this, Denso North America Canada developed a spray application approval programme which mandated that a spray applicator intending to administer Protal 7200 complete both theoretical and practical training before undertaking any work using the product. The theoretical training included reviews of product data sheets, material safety data sheets (MSDS) and the spray application specification, while the practical training included surface preparation followed by the application of Protal 7200, as per the spray application specification. The applied panels were then sent to a third-party test lab, where cathodic disbondment and hot soak adhesion testing were performed. Based on the results of these tests, the application company was either deemed to have passed or failed.

A new standard for field-applied coatings

In 2014, the Canadian Standards Association Group (CSA) introduced the CSA Z245.30-14 standard for field-applied external coatings for steel pipeline systems. This standard covered the application of coatings and related activities for steel piping, both in the field and in the shop, and set higher minimum requirements for manufacturers, applicators, and owner groups to attain to. These minimum requirements included performance obligations for coating manufacturers to comply with, as well as applicator training, documentation, and more…

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