Cast iron flanges are available in which of the following pressure ratings?

The correct pressure ratings for cast iron flanges include 25, 125, 250, and 800. These ratings indicate the maximum pressure that the flanges can safely handle, which is crucial in ensuring the safety and reliability of pipe systems.

In various applications, cast iron flanges are primarily used in lower pressure situations, making the specified ratings more appropriate. Understanding these ratings will help in selecting the suitable flange for specific plumbing, heating, or industrial applications, ensuring systems operate efficiently under expected pressure conditions.

The other options suggest pressure ratings that are not typically associated with cast iron flanges or include higher pressures than what is generally safe for this material. For instance, ratings like 1500 or those that exceed the 800 mark in a more typical setting may not align with cast iron's structural capabilities, as cast iron is more commonly found in lower pressure applications.