Flexible piping used in these systems must be?

• A. Of approved materials and pressure ratings
• B. Of any material as long as flexible
• C. Only stainless steel
• D. Not require pressure ratings

Answer: (A)

Flexible piping in clean agent systems must be of approved materials and have defined pressure ratings. This requirement ensures the piping can safely contain the extinguishing agent at the system’s operating pressures and potential surge conditions, while also being chemically compatible with the agent to prevent degradation, leaks, or ruptures. Approved materials have been tested and listed for use with the specific agent, providing confidence in long-term performance, temperature resilience, and mechanical integrity. Using non-approved materials or skipping pressure ratings introduces risk of leakage, failure, or unwanted reactions, which could compromise discharge effectiveness and safety. Therefore, the correct practice is to use flexible piping that is specifically approved and rated for pressure.