3. Nonlinear Design Evaluation Alternatives – Class 2 and Class 3 Piping Available to Purchase

The general design evaluation rules for Class 2 piping are given in ASME III in articles NC-3600, and NC-3652 through NC-3655. The rules for Class 3 piping, given in articles ND-3600 of the Code, are basically the same as those for Class 2 piping (NC-3600). (See Slagis for an excellent review.) Stress limits are identical. We note minor differences regarding some requirements (for example, welding requirements), but significant differences regarding other requirements (for example, material quality requirements). For structural design evaluation for mechanical, thermal and other secondary loads, requirements and criteria for Class 2 piping are applicable for Class 3 piping.