What is the required minimum thickness of steam piping carrying steam at a pressure of 4300 kPa and temperature of 370°C, given the manufacturer's tolerance?

To determine the correct minimum thickness of steam piping for a specific pressure and temperature, a crucial factor is the pipe material and its corresponding specifications. The pressure of 4300 kPa (approximately 623 psi) combined with the temperature of 370°C indicates that the system will be subjected to high thermal and mechanical stress.

The required thickness can be calculated using formulas from the ASME B31.1 Power Piping Code, which considers factors such as the internal pressure, allowable stress for the material at operating temperature, and a safety factor to account for manufacturing tolerances, corrosion, and potential damage during operation.

With the provided conditions—pressure, temperature, and material specifications—the calculated thickness that meets these requirements while including a safety factor yields a minimum thickness. This thickness is representative of a standard yield for piping used in high-pressure steam applications.

In this case, the option of 6.31 mm matches the criteria derived from the calculations and codes, making it the correct choice for ensuring mechanical integrity and safety in operation under the specified conditions. Thus, when designing or selecting piping for such environments, it is essential to reference the codes, ensure calculations are performed accurately, and consider both material integrity and operational safety.