What is the pressure rating of a 300# flange?

The pressure rating of a 300# flange is truly 740 psi at high temperatures. Flanges are classified by their pressure-temperature ratings according to industry standards, such as those set by the American National Standards Institute (ANSI) or the American Society of Mechanical Engineers (ASME).

In this case, a "300#" designation indicates that the flange is suitable for a service pressure of 300 pounds per square inch (psi). However, the actual pressure it can handle can vary with temperature. When using a 300# flange at elevated temperatures, the maximum pressure at which it can operate safely is determined to be around 740 psi.

This value reflects the combination of the material properties and temperature conditions outlined in the applicable pressure-temperature rating charts. Understanding these ratings is crucial for ensuring the safety and reliability of piping systems, particularly in high-pressure applications.