Where used, flexible pipe, tubing, or hoses, including connections, shall be of what?

• A. Must be of stainless steel only
• B. Must be of approved materials and pressure ratings
• C. Can be any material
• D. Must be rigid

Answer: (B)

In clean agent systems, every flexible pipe, tubing, or hose and its connections must be made from approved materials and have appropriate pressure ratings. This requirement ensures that the entire delivery path is chemically compatible with the agent and strong enough to withstand the system pressure without failure. When the material is approved for the specific agent and is rated for the operating pressure, you reduce the risk of leaks, swelling, or rupture that could undermine the discharge and effectiveness of the release.

Choosing only stainless steel would be too restrictive and ignores the reality that many approved flexible materials (including certain elastomers and plastics) are acceptable when they are listed for the agent and pressure involved. Saying any material would be unsafe because it could include incompatible or inadequate options, and insisting on rigidity would ignore legitimate needs for flexible connections in many layouts. The key point is compliance with approved materials and pressure ratings to maintain safety and performance.