What is the minimum extension required for a protective steel plate over a notched or bored steel pipe?

The correct choice aligns with industry standards that specify the minimum extension for a protective steel plate over a notched or bored steel pipe. A minimum extension of 4 inches on each side provides adequate coverage to ensure that the structural integrity of the pipe is maintained while also protecting it from potential damage during installation or operation.

This extension is critical because the notching or boring of a pipe can create weak points that could be susceptible to failure if not properly shielded. The additional coverage acts as a safeguard, distributing any impact or load more evenly and helping to prevent stress on those weakened areas. Following this guideline is important for ensuring safety and reliability in gas fitting applications, as it helps prevent potential leaks or failures that could arise from compromised piping.

Other options would either provide insufficient protection or unnecessarily high coverage that exceeds standard safety practices, thus reinforcing why 4 inches is the most practical and established requirement.