Here is my thought process...
- When computing required thickness using unit forces calculations, it shouldn't matter if the thickness is a single layer or multiple layers assuming the resulting unit force is in tension and each layer is at least 3/16".
- The top layer (reinforcing plate) would be equivalent to a double fillet weld joint efficiency (E or JE) of 0.70 and the bottom layer (existing cone) has a 0.85 JE. Even though the combined joint configuration is not specifically covered in API 620, Table 5-2, taking the lower of the two JE (0.70) as the combined JE should be a safe practice.
- Given the aforementioned thought process, am I violating the letter or intent of API 620?
- What suggestions/comments/advice can be offered?
- Am I completely off base with this line of reasoning?