NACE MR0175/ISO 15156 gives requirements and recommendations for the selection and qualification of carbon and low-alloy steels, corrosion-resistant alloys, and other alloys for service in equipment used in oil and natural gas production and natural gas treatment plants in H2S-containing environments, whose failure could pose a risk to the health and safety of the public and personnel or to the equipment itself.
The “Weakest Link” on any structure is found at the nut and bolt assemblies. Nuts and bolts are found on every structure. “The fate of any complex steel assembly may be determined by the vulnerability of its smallest and least considered components”. “The bolts or fasteners holding the assembly together are often the areas where corrosion starts first and where the effects of corrosion may have the most serious consequences”.