Materials Performance Supplements

TANK 2018

Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

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26 MAY 2018 W W W.MATERIALSPERFORMANCE.COM TANK CORROSION CONTROL SUPPLEMENT TO MP primer that was not visible to the eye and could be viewed only when blowing the sur- face or at the end of each spray pass. This powder presented as fine clouds, mostly visible when crossing natural light. The specification requested a tolerance rating ≥2, which requests removal of visible dust as described in the standard but doesn't deal with nonvisible dust. This contamination was widespread and presented a significant risk to the coat- ing adhesion. The head contractor along with the applicator said, "The specification says we only need to supply four compliant tape tests, and we have achieved that." This situation was difficult because the client hadn't provided me with authority, and the specification didn't effectively deal with dust contamination. I first asked the client to provide a site instruction to include the recleaning of any areas of surface dust found to not comply with the specification. Second, I asked the coatings manufacturer if it would endorse application over a powdery dust layer. The coating manufacturer's response hit my inbox before the client could get back to me. Obviously, the answer was a resounding "no." When this was confirmed via email, I for warded it to all parties and recom- mended that the coating application be halted until cleanliness was achieved. During this time, the applicator had applied coatings to 25% of the tank's floor area. I did not have the authority to prevent this work; however, through my effort, the team decided to reclean the remaining floor area. Strictly speaking, a nonconformance was not applicable; however, all informa- tion was captured in my report for future reference, and the client responded by thanking me a few weeks later. Excellence and Improvement A coating inspector does not perform surface preparation, provide materials, nor apply coatings. Nor does he or she provide a warranty or guarantee of the coating per- formance. Our role as coatings inspectors is to observe, inspect, test, and report. We are, however, requested to observe the project documentation and report compliance and noncompliance in accordance with the specification, standards referenced, manu- facturers' data sheets, and written site instructions. O n projects w h ere w orkmanship i s poor, our inspection reports should include twice as much data to describe tasks per- formed and project difficulties. I recom- mend that every inspector be vigilant in providing a daily site diary of tasks per- formed and project difficulties, especially on projects where your authority or the specification is insufficient. A d d i t i o n a l ly, a n i n s p e c t o r s h o u l d d e scri b e go o d w orkm an ship—w ith out endorsing coating performance—and high- light practices used to provide high-quality work. For example, I was engaged by a client who needed to improve the quality of the coating application in order to achieve increased durability. The asset is a network of buried mild steel oil transmission pipe- lines in Australia. The owner had endured a history of poor applications, including runs and inclusions because the field staff cul- ture believed it would "just get buried any- way." Each dig required the removal of exist- ing coatings, usually coal tar enamel or two-layer polyethylene (yellow jacket), fol- lowed by nondestructive material testing of the metal surface. Once the pipe was con- firmed fit for AS 2885.3, 3 "Pipelines—Gas and Liquid Petroleum Operation and Main- tenance," it was prepared and recoated in accordance with the owner's specification document. Over the course of two years, there have been 84 digs of this type, and we have been successful in providing on-site inspection of hold points. Each report has a section for "Items of Excellence" and a section for "Items for Improvement." Items of excellence included: • Use of canopi e s for prot e ction during inclement weather • Use of plyboard panels for flooring in each dig to — Keep either mud or dust from contaminating the surface — Provide a cleaner work envi- ronment for applicators • Self-inspection by the applicator in between inspection points Photo courtesy of Justin Rigby. Tank Protection Articles

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