What is the maximum pipe size (in inches) below which diameter must be non-corrosive?

What is the maximum pipe size (in inches) below which diameter must be non-corrosive?

• A. 1/4
• B. 3/8
• C. 1/2
• D. 5/16

Answer: (B)

The rule targets corrosion risk in small-diameter piping: smaller branches are more prone to corrosion issues that can clog lines and shorten life, so the system specifies that pipes meeting this limit must have a non-corrosive interior. The largest size that falls under this requirement is three-eighths of an inch. That means any branch line at or below this diameter must use non-corrosive pipe or have a non-corrosive lining. Larger sizes don’t carry this particular requirement, and the other options are either below or above the threshold but do not represent the maximum size that triggers the rule.

The rule targets corrosion risk in small-diameter piping: smaller branches are more prone to corrosion issues that can clog lines and shorten life, so the system specifies that pipes meeting this limit must have a non-corrosive interior. The largest size that falls under this requirement is three-eighths of an inch. That means any branch line at or below this diameter must use non-corrosive pipe or have a non-corrosive lining. Larger sizes don’t carry this particular requirement, and the other options are either below or above the threshold but do not represent the maximum size that triggers the rule.