Downstream Corrosion Blog

 

  • Downstream Corrosion Blog

    August 23, 2018

    How Doxsteel Fasteners Resist Refinery Corrosion

    Regardless of the application, corrosion is a constant enemy to bolting operations. When oxide accumulates in the thread engagement between a stud, nut, and equipment, the only way to free the fastener is through exotic removal processes such as metal disintegration or single stud hot bolting. Due to the high risk facing workers in these conditions and the extended downtime that threatens profitability, these dangerous and time-consuming turnaround practices are a death tax to facilities.


    Even if a petrochemical refining or power generation facility is located in an arid climate, certain necessary equipment causes corrosive environments to form in some areas. Sulfides and sour water produced by cooling towers, compressors, valves, vessels, and pumps can easily compromise thread engagement and even lead to hydrogen embrittlement if bolting is not properly protected. In the worst circumstances, bolt failure of this kind can lead to costly and catastrophic outcomes.


    Nickel-Cobalt Alloy: Resistant to Seizing and a Barrier to Hydrogen


    While there is no way to make a bolt that will last forever, proper manufacturing practices and strong fastener coatings can extend a bolt’s life cycle and allow a facility to predict how long it will last before seizing. Even if a maintenance team can execute turnaround operations one day before corrosion compromises thread engagement, a facility would see significant cost savings and avoid putting its workers at risk. That’s why we recommend carbon steel bolting that is electroplated with Nickel-Cobalt alloy following ASTM B994 SC18 Class 1 specifications.


    With ASTM B994 Nickel-Cobalt bolting, facilities can eliminate costly and unconventional bolting turnaround solutions by protecting thread engagement. Where sour water elements like ammonia and hydrogen sulfide attack lesser coatings and increase the risk of hydrogen embrittlement, ASTM B994 SC18 Class 1 bolting acts as a barrier to hydrogen. With rigorous control and constant testing of bolt manufacturing practices, companies that use ASTM B994 fasteners can accurately predict the life cycle of their bolts so they can replace them before they seize. The coating’s low coefficient of friction helps prevent galling and provides k-factor consistency, making it easier to apply the proper torque for the job, and ASTM B994 SC18 Class 1 bolting can operate in temperatures ranging from -328°F to 1300°F without compromising its coating.


    Use Doxsteel Fasteners to Schedule Maintenance with Certainty


    When bolting seizes, the cost of turnaround has no ceiling. However, with unparalleled corrosion protection, Doxsteel Fasteners eliminate excessive petrochemical refinery downtime and worker risk caused by seized bolts. We stand by this promise with a warranty that guarantees our bolting will not seize for five years. However, extended testing practices coupled with constant innovation lead us to estimate that our bolts will continue to protect thread engagement far beyond the life of their warranty.


    To learn how your petrochemical refinery or power generation facility can benefit from bolting that stands up to corrosion, contact Doxsteel today.