NACE SP0170 provides the roadmap to prevent this entirely.
In simple terms: When you have a carbon steel pipe or vessel handling hot, sulfur-containing hydrocarbons (typical in crude units or hydrotreaters), the weld area is chemically different from the base metal. It corrodes much faster. NACE SP0170 tells you how to stop that—usually by applying a corrosion-resistant alloy (CRA) weld overlay. nace sp0170 pdf
Two years ago, a rival engineer had specified a standard epoxy coating under the saddle. But SP0170, buried in a non-mandatory appendix most people ignored, had a footnote: “For elevated temperature service above 400°F, mechanical isolation is preferred over coatings alone.” NACE SP0170 provides the roadmap to prevent this entirely