What material is the steam feedwater pipe made of when its required thickness is calculated to be 11.85 mm?

The steam feedwater pipe is typically made of materials that can withstand high pressures and temperatures associated with steam systems, while also offering good mechanical properties and corrosion resistance. When evaluating the material suitable for a feedwater pipe, it is essential to consider both the mechanical and thermal characteristics of the material.

SA-209 Grade T1 is a specification for low-alloy steel tubes intended for high-temperature service, making it an appropriate choice for steam feedwater piping. Its design allows for safe operation under very high temperatures while maintaining adequate strength and toughness, which are crucial for the integrity of the piping system in a steam boiler application. The thickness requirement of 11.85 mm aligns with the properties of SA-209 Grade T1, ensuring that the pipe can handle the operational stresses it will encounter.

The other materials listed, while they have their uses, may not completely fulfill the requirements for a steam feedwater pipe at high temperatures and pressures. For instance, SA-335 P11 and SA-335 P7 are typically used for alloy steel pipe, but they may not be the best choice for feedwater applications compared to SA-209 Grade T1. SA-285 C, on the other hand, is more suited for low-to-medium pressure service and might