Many facilities believe putting a flange together is far easier than paying for a “certified weld” joinment. They see this as a low-risk, cost-saving solution, believing any “maintenance mechanic” can put a flange together. Hence, most LOPC events I have had in my time were due to a flange that was NOT assembled per ASME B31.3. This article is for safety professionals seeking to understand the fundamentals of B31.3 as they apply to flanges. Keep in mind, this goes FAR BEYOND PSM/RMP requirements.