Each pipe section shall be cleaned internally after preparation and before assembly by means of swabbing, utilizing a suitable nonflammable cleaner. The pipe network shall be free of particulate matter and oil residue before installation of nozzles or discharge devices. How should the pipe sections be cleaned prior to assembly?

• A. By swabbing with a suitable nonflammable cleaner
• B. By washing with water
• C. By sandblasting
• D. By chemical etching

Answer: (A)

Cleaning the pipe interior by swabbing with a suitable nonflammable cleaner is the proper method because it directly removes both particulates and oil residues from the inside surfaces without introducing moisture or leaving harmful residues. This approach keeps the interior dry and clean, which is essential before installing nozzles or discharge devices in a clean agent system.

Washing with water can leave moisture that may promote corrosion or affect system performance and cleanliness. Sandblasting would damage the interior surface and generate dust or debris to be cleaned up later. Chemical etching could leave chemical residues that might react with the agent or require extensive post-cleanup. Swabbing provides effective cleansing while maintaining compatibility with NFPA 2001 requirements.