Pipeline Perspectives — Solutions to the Corrosion of Trust
By Ken Grantham
Corrosion is the most imminent and harmful problem affecting the North American energy, petrochemical and utility sectors, from upstream to downstream operations and especially pipeline resource transportation. The North American oil and gas pipeline industry’s first step in combating corrosion must be to shift away from the material compositions of yesteryear and on to next generation solutions designed to ease preventative maintenance and make integrity management programs more practicable.
The March 12 natural gas pipeline explosion in Harlem, New York, is a stern wake-up call, not only to families living in what they thought to be their own, safe apartments and homes, or even local utility companies and energy service providers, but for the entire pipeline industry.
Due to the natural gas explosion, eight residents were killed, dozens more were injured and hundreds are still displaced after the destruction of two buildings.
A National Transportation Safety Board (NTSB) report on the explosion revealed the main in question was a 127-year-old, 8-in. diameter cast iron pipe. As an engineer overseeing technical services for an ever-evolving metals producer serving various high-corrosion industries, I can say with surety this is one of the most easily corroded and crack-prone metals unfortunately still in operation.
Not only should we as pipeline engineers, contractors and suppliers rethink our approach to this increasingly criticized problem for professional purposes, but for the reason that we are those same families living in what we thought to be safe apartments and homes. As an industry, we do not have to stand for this.
The advancements in design, technology and maintenance operations in both the North American oil and gas pipeline and metallurgy industries in recent decades cannot be disputed. We must harness this progress in order to prevent any similar tragedies in the future. It is our duty as an industry to use proven technological developments to guarantee the safety of our families, the professionals developing and constructing pipeline infrastructure and to complete our assigned task of resource transportation both above and below ground.
Specifically, newly developed stainless steel grades and products have been designed to help combat the intense effects of corrosion, and they are already available to the North American oil and gas pipeline industry. Living and working in the state of Louisiana, where we are in the midst of a predicted $50-$60 billion petrochemical boom, I cannot emphasize enough that now is the time to take full advantage and marry new metallurgy technology to new opportunities in the pipeline industry.
Not only are these new grades of stainless steels applicable to the technical pipeline projects we deal with on a daily basis as professionals, but they will also resonate with the general public.
It is the metals industry’s current mission to educate both design engineers and corrosion experts directly consulting with the pipeline industry on the recent advancements in metallurgy and next generation materials. The most recent corrosion-resistant stainless steel grades have come on to the market in order to offer much more than improved corrosion resistance and lower life cycle costs, but to help reduce the sheer volume of preventative maintenance being performed in today’s pipeline industry, as well as to make the duties of integrity management programs more feasible.
Maintenance managers’ missions are made more difficult on a daily basis as a result of pitting corrosion and stress corrosion cracking. Next generation materials are focused on combatting pitting corrosion resistance versus traditional grades of stainless steel or even coated metals. This is another enormous nuisance in industry today and these emerging grades are engineered specifically to solve these problems. Emphasis must be placed on the material’s significantly decreased susceptibility to stress corrosion cracking, which is yet another burden as it relates to our industry’s integrity management systems.
The pipeline industry is growing by leaps and bounds, and we should be focused on new planning, development and construction, while remaining confident the pipelines we have already installed will require the least amount of preventive maintenance and can easily be cared for by integrity management systems.
In service, the development of these new stainless steel grades, generate savings in maintenance, improved productivity and longer service life. In a wide variety of applications, they have already been extremely successful in displacing metals such as coated carbon steel, weathering steels and aluminum. Each case demonstrates a realistic performance or economical advantage, often both.
New grades were researched and designed specifically to impact the total life cycle cost of equipment. While these metals are certainly cost effective on the front end, their benefit is even more impressive on the back end helping to reduce future costs, including preventive maintenance, raw materials, labor and downtime and in some cases even the removal of compromised equipment from service.
As we know, the pipeline industry also undergoes much stress in regard to heat transfer. Newly developed grades of stainless steel have several notable characteristics at elevated temperatures: Reasonable mechanical properties; good scaling and oxidation resistance, including resistance to sulphur-bearing atmospheres for aboveground piping; negligible embrittlement after extended exposure to high temperatures; and resistance to many hot gases and fumes generated in various industrial processes.
On a daily basis, the oil and gas pipeline industry is fabricating and altering pipelines to fit design engineering plans, specifically welding and forming. Next generation materials were crafted to meet the range and demands of these tasks, so weldability and formability were two traits specifically taken under consideration in their development. This makes these grades capable of fabrication by conventional techniques. The substantially austenitic microstructure at elevated temperatures also restricts grain growth during welding, which leads to a tough duplex ferritic heat affected zone.
The decision-makers involved on the business side of the next generation solutions development also considered their counterparts in the purchasing departments of the oil and gas pipeline industry as the new grades serves as a price stable alternative to high nickel stainless steels. With projects and materials being quoted at such a rapid pace, stability is needed in making purchasing decisions and cost stability cannot be underestimated.
The next generation grades are no doubt cost stable stainless steels as a result of newly developed chemical compositions. The materials are not subject to erratic price fluctuations simply because they do not depend upon expensive alloying elements like nickel and molybdenum. New material grades have maintained a consistently lower cost advantage compared to other corrosion-resisting materials, all while helping to reduce costs by eliminating the need for protective treatments and material corrosion allowances. There may be nothing more helpful for maintaining ever decreasing project budgets and planning than trustworthy cost stability.
Decision-makers and project managers may also be interested in the increased strength the new materials have gained, allowing for potential weight reduction. Not only will this increase construction and pipe placement operations, but it allows for lower freight weights and fabrication costs.
While the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) regulates pipeline safety, it’s up to the pipeline operators to “know, understand and manage the risks associated with their own pipeline facilities.” At current pipeline construction rates, the North American oil and gas pipeline industry will not only need to adapt to handle the sheer volume of incoming projects, but set the example for the regulators that our industry is taking the necessary steps to be at the forefront of innovation and lead all divisions of energy and utility industries in safety precaution.
I regularly travel the globe to visit various conferences and companies — both in the metals and pipeline industries — and I have seen exceptional advances in engineering and metallurgy.
The North American oil and gas pipeline industry does not have to take a reactive approach to encroaching corrosion prevention and maintenance when the materials needed to specifically combat this industry-threatening problem have been created.
Ken Grantham is executive vice president and director of technical services at Crompion International, which produces and distributes Cromgard specialty stainless steels. Since 2008, Grantham has managed quality and process controls, maintained ISO 9000:2008 accreditation, expanded value added product and service offerings and added 3D modeling and simulation capabilities.
