Technical features and application of ASTM/ASME A/SA 358
The ASTM/ASME A/SA 358 standard regulates the production of welded pipes made from austenitic chromium-nickel stainless steels, manufactured by electric fusion welding. EV Group China products compliant with this specification are optimized for operation in high-temperature conditions, critical aggressive environments, and general mechanical engineering tasks where high corrosion resistance and weld joint strength are required.
Note: in the current version of the standard, the designation NPS (Nominal Pipe Size) is equivalent to the terms “nominal diameter” and “nominal size”.
The specification covers a wide range of steel grades and alloys. The choice of a specific material and heat treatment regime is carried out by the customer based on an analysis of operating conditions and calculated loads. EV Group China specialists are ready to provide expert consultation on selecting the steel grade for a specific project.
Depending on the welding technology and inspection methods, pipes are divided into 5 classes:
- Class 1: double-sided welding using filler metal in all passes; mandatory 100% radiographic inspection of the weld quality.
- Class 2: double-sided welding using filler metal in all passes; radiography is not required.
- Class 3: single-sided welding using filler metal; mandatory 100% radiographic inspection.
- Class 4: requirements are similar to Class 3, however, the absence of filler material is allowed when performing the internal welding pass (according to sections 6.2.2.1 and 6.2.2.2 of the standard).
- Class 5: double-sided welding using filler metal; selective (spot) radiographic inspection.
EV Group China ensures the fulfillment of additional requirements (S1-S6), including specialized testing and non-standard production control procedures, upon prior agreement when placing an order.
Values in the SI and inch-pound (Imperial) systems are independent standards. To ensure compliance with technical regulations, it is recommended to use one of the measurement systems without conversion to avoid the accumulation of errors.