What is the acceptable type for stainless steel used in fittings?

Type 304 stainless steel is widely recognized as a suitable choice for fittings in compressed natural gas applications due to its excellent corrosion resistance and good mechanical properties. This type of stainless steel contains a significant percentage of chromium and nickel, which enhances its overall durability against harsh environmental conditions and corrosive substances that may be present in CNG systems.

In particular, Type 304 has a strong resistance to both oxidation and corrosion, making it ideal for use in fittings, piping, and other components that will be exposed to varying atmospheric conditions and the specific chemical characteristics of natural gas. Additionally, Type 304 is easier to form and weld compared to other grades, making it a practical option for manufacturing fittings.

While other types of stainless steel mentioned have their own specific use cases, Type 304 stands out for CNG fittings due to its balance of properties that are advantageous in gas transport and handling applications. For instance, Type 316, while having superior corrosion resistance due to its molybdenum content, may be more expensive and is typically reserved for environments with higher salinity or chlorides. Type 202 and Type 321, while suitable for certain applications, do not offer the same level of corrosion resistance as Type 304 for the conditions typically encountered in C