Water containing solids likely to clog discharge devices but otherwise acceptable for making foam shall be permitted to be used after passing through line strainers.

• A. Not permitted
• B. Permitted after line strainers
• C. Permitted after chemical treatment
• D. Permitted after carbon filtration

Answer: (B)

In foam-water systems, if the water contains solids that could clog discharge devices but is otherwise suitable for foam, it is allowed as long as those solids are removed by line strainers. The key idea is to protect the foam-distribution components—like eductors, foam generators, and discharge nozzles—from blockage without altering the water’s foam-forming properties. Line strainers provide a simple, mechanical filtration that removes solids before the water enters the foam solution, keeping the system reliable while avoiding chemical changes or additional filtration stages that aren’t specified for this case.

Other filtration or treatment methods aren’t needed here because they can change the water chemically or remove substances that might affect foam quality, and the standard explicitly supports using line strainers for this scenario. Not permitting this would ignore the practical protection line strainers offer, while alternative treatments aren’t required for the situation described.