How often must cleanouts be installed for each change in direction in a run of drainage piping?

The correct choice specifies that cleanouts must be installed for every change in direction in a run of drainage piping at intervals not exceeding 40 feet. This requirement serves several important functions in plumbing systems. The primary purpose of cleanouts is to provide access for clearing blockages and maintaining drainage systems. By ensuring that there are cleanouts at these intervals, plumbers can effectively manage potential clogs and facilitate maintenance.

In addition to providing access points for cleaning, the requirement for intervals up to 40 feet helps to prevent the accumulation of debris in the piping system, thereby reducing the likelihood of future blockages. This spacing is considered adequate for typical drainage systems, allowing sufficient access without excessive installation of cleanouts, which can increase costs and complexity.

Understanding this standard is crucial for ensuring compliance with plumbing codes and maintaining effective drainage within a plumbing system. It reflects a balance between accessibility for maintenance and practicality in system design.