Advances in pipeline coating systems

By Michael Osborne, President of Nukote Coating Systems International

Superior anti-corrosion systems have been developed for use in the internal and external coating of pipelines. This coating system technology is comprised of advanced polymers, which have been designed and tested specifically to fit the special requirements of pipelines and the petrochemical media being distributed. These polymers include specific polyurea, polyurethane and hybrid polymers that exhibit properties desirable in anti-corrosion systems, at minimum meeting the physical properties common to traditionally specified systems and in most cases far exceeding them. These products physical properties are readily adjustable and can be tailored to meet the specific requirements of the end-user.

These advanced polymers have been utilized in pipeline projects worldwide but as yet are not widely specified by major oil and gas companies. This situation is not uncommon to new technologies, as a period of time from development to acceptance is a standard obstacle typical to most industries. When these products were first introduced to the market there were many obstacles in place that limited the products wide acceptance. These obstacles included lack of qualified application equipment systems, cost effectiveness of the systems compared to traditional coatings and resistance to the new technology by companies promoting traditional coatings. The principal obstacles have been overcome with production and field equipment systems development in place that provides consistent, efficient application of the products, the cost of the products are currently extremely attractive to end-users when compared to traditional coating systems and resistance from competing products is being eroded by a growing acceptance by end-users. Qualified product manufacturing, production coating facilities and experienced field applicators are presently available worldwide. These products will become commonly specified, the question now being not if this will occur but when.

It is common knowledge that no traditional anti-corrosion system is completely meeting the needs of the end-user. Traditional products are specified because they are deemed to be the “best that are available”. The author contends that this may have been the case 5 or even 10 years ago, but it is not the case now and that use of many traditional coating products is being maintained due to a failure of the end-users to properly research and investigate the newer technologies available. This situation is exacerbated by the larger pipeline coating companies, which form what is essentially an oligopoly desiring to maintain the status-quo and recover their significant investment in equipment systems required to apply traditional coatings, prior to changing over to more modern coating systems and that initially the newer technically advanced coatings were primarily represented by smaller companies without the technical resources, worldwide representation and financial strengths required to achieve significant market penetration.

The facts are that the newer coating technologies can provide end-users with anti-corrosion coatings for pipeline systems with: much higher physical properties providing the end-user with longer investment maintenance and reduced costs over time, reduced instance of damage during installation, higher levels of corrosion resistance, higher levels of chemical resistance, higher process temperature ranges, faster application and installation, better field joining methods and above all lower costs. There are now companies representing these newer technologies that: are reputable, have invested the time and resources to formulate products specifically for pipeline applications, provide representative product information and are capable of delivering completed coating systems inclusive of the required technical expertise, production capacity and quality assurance and control required for projects of this nature. Time and effort should be expended to carefully review the potential of these newer coating technologies, with the goal of achieving industrial standards, application standards and other criteria to reach worldwide acceptance of the products as a minimum as an alternate system to the traditional coating systems commonly in use.

Pipeline anti-corrosion applications represent what is probably the largest worldwide volume market for coatings products. This market potential naturally draws the focus of every coatings manufacturer, distributor and applicator and for these companies; the successful penetration of this market segment represents large product sales volume increases over an extended period of time. Since large volume sales are the primary goal of every manufacturer, the end-user is bombarded with product marketing information all claiming their product alone is best suited for pipeline anti-corrosion applications. The sheer volume of information available on this subject can be overwhelming for the end-user, making a decision to select a specific product difficult to reach. The situation is further compounded by typical factors inhibiting new technology acceptance, which include: time required for new technologies to achieve a standardization recognized by the end-user, end-user reluctance to try new products prior to a lengthy historical performance of the product in field applications, and resistance of large pipeline coating corporations to adopt new products prior to recapturing initial investments in equipment utilized to apply traditional coatings.

In addition to the reasons defined above, there are many other non-typical factors that delay the wide acceptance of new coatings technology in pipeline anti-corrosion applications. All multi-national oil and gas companies, which represent the first step in product acceptance, are not only conservative regarding new product technologies, but are also large in structure and require time-consuming product technical approvals and field trials. Due to the size of investment required for pipeline installations, the conservative approach and requirement for field trials is not surprising, but when this lengthy approval process is combined with a plethora of coating companies bombarding the decision makers with marketing data that is based on conjecture, unsubstantiated or even false information regarding the product offerings, reaching a decision can be very difficult.

Significant marketing efforts have been expended by manufacturers to promote the features and benefits of their specific formulations over others causing a considerable amount of confusion with the end-users. Polyurethane manufacturers direct their efforts towards de-emphasizing the benefits of the newer polyurea technology while polyurea manufacturers emphasize certain aspects of their products to highlight perceived weaknesses of polyurethanes. For end-users the keys to solving this information quagmire is to determine internally what physical property levels they require and base their product selection on formulations that meet these guidelines, at costs that are acceptable, via manufacturers who have proven formulations specifically designed for the application and installed by applicators experienced in pipeline coatings.

The oil and gas industry, as a whole, is extremely conservative in approving new products for use as anti-corrosion protection systems. There is no clearer indicator of the level of conservativeness of this industry than the fact that the latest technology widely utilized in anti-corrosion coatings for pipelines is 14-years old and this technology in typically utilized in only high-abuse applications. For less demanding applications, such as low-temperature trunk lines, the technology most commonly utilized has been in place since 1975. If an attempt were made to find an industry whose leading companies commonly utilize what amounts to old technology, it would be difficult to achieve. This conservativeness is based, to a large extent on historical failure rates of older anti-corrosion systems.

Anti-corrosion coating failures are a significant factor in reduced operational life of pipelines. The failure of a pipelines coating system accelerates corrosion and can result in leaks requiring repair, cleanup and in some cases replacement of the pipeline. The costs of repair and replacement are significant, as are costs associated with spill containment and cleanups. The cost, environmental impact and negative publicity associated with failures are something every major oil and gas company seeks to avoid. In the past 10-20 years, failure analyses of pipelines have been performed by a variety of companies, agencies and special interest groups, in an effort to reduce or eliminate failure incidents. These analyses are public information and contain a variety of good data, some of which is relevant when determining whether or not to utilize newer technologies. Failure analysis data can be feasibly applied only to coating systems that have been in wide use over a period of time. The data derived from the studies of pipelines in operation for 20-years or more are conclusive while evidence on pipelines operating for a shorter duration may not be as clear. The overwhelming evidence of this data clearly shows that traditional coating systems commonly utilized are not performing over the design life of the system exhibiting consistently high failure rates resulting in either major repair works or replacement of expensive distribution systems.

The use of many traditional coating products has been discontinued in recent years for a variety of reasons including cost, durability, environmental concerns, etc. FBE and tri-laminate products are presently the dominant anti-corrosion systems specified and utilized in most pipeline coating applications. FBE products are commonly specified for lower temperature, lower abuse and lower budget applications. Tri-laminate products are commonly specified in higher temperature, higher abuse applications. The current use of more expensive tri-laminate products in high abuse applications is a clear indicator that the extended performance and durability FBE is known to be insufficient to the task. Tri-laminates, which are essentially a Fusion Bonded Epoxy anti-corrosion system with an added layer of polyethylene or polypropylene, indicate that the anti-corrosion properties of FBE are satisfactory thus the development of the added protection layers to offset the weaknesses of the product as a stand-alone system.

Advanced polymer products exhibit physical properties that meet and in most cases exceed the properties of FBE and tri-laminates, especially in regards to damage during installation and subsequent failures resulting from this initial damage to the integrity of the installed system. These products are competitive with FBE and significantly less expensive than tri-laminates and are available worldwide with production facilities and qualified applicators available in virtually any location. The products production and field joining processes are simple, consistent, seamless and durable. Volume production can be accomplished consistently on site reducing logistics costs and damage instances common to shipping and handling of pre-coated pipe sections. The combinations of these features clearly meet the specific needs of the end-user and resolve problems common to currently specified products. So why then are they not more commonly specified?

Advanced polymers are presently not commonly specified because they are a new technology; end-users are cautious when specifying products and are far more comfortable using something they are familiar with. There is a lot of industry confusion in regards to polyurea and polyurethane products, much of which is generated by the competing manufacturers own marketing information and sales tactics. Large coating companies will not retrofit their facilities, regardless of the low costs required to add polymer coating capabilities, until the end-users start specifying these products consistently.

It takes time for new technologies to become common. The features and benefits provided by advanced polymers, combined with their lower costs cannot be ignored. The products are being specified more and more commonly and will soon become as familiar to end-users as traditional coatings. Major coating companies will retrofit their facilities and offer advanced polymers along with traditional coatings in direct relation to the end-users prevalent acceptance and specification of the products.

It is the responsibility of the end-user to determine the best system for use in their unique project in accordance with its specific requirements. Specifying traditional coating systems with known performance weaknesses and unacceptable failure rates, simply because they have been utilized for longer periods of time seems illogical. Modern industry is based in the development and implementation of new technologies to enhance productivity and reduce costs. For the Oil and Gas Industry, failing to take the necessary steps required to research, test and implement newer technologies, then specifying traditional technologies because they are familiar (even when not effectively providing the solution required), must be corrected. The process of testing and implementation of these new technologies will result in their common acceptance globally and this process is driven by the end-user.

Nukote Coating Systems manufactures and distributes advanced polymers designed for use in anti-corrosion systems for internal and external pipeline anti-corrosion applications. The products have been used and are specified by many oil and gas companies. Nukote distributors and affiliates have product manufacturing facilities, qualified applicators and production coating facilities in locations as diverse as China, Indonesia, the Middle East, North America and Europe. Complete technical programs, quality assurance programs, product data, test data and historical performance information are available upon request.