During post-installation testing, which result indicates proper proportioning?

During post-installation testing, which result indicates proper proportioning?

• A. System color coding matches project drawings.
• B. Leakage is absent from all joints.
• C. Foam solution discharge matches the expected rate.
• D. Proportioning accuracy is verified.

Answer: (D)

During post-installation testing, you want to confirm that the foam concentrate and water are being mixed in the designed ratio. Verifying proportioning accuracy does exactly that: it checks the actual foam solution concentration at the discharge against the specified design percentage (for example, 3% or 6%). When this ratio is confirmed correct, the foam solution will have the intended properties and performance for fire control. Other checks, like color coding or verifying that there is no leakage, relate to documentation or system integrity, and while important, do not prove that the foam concentrate is being proportioned correctly. Even if the discharge rate matches an expected value, the concentration could still be off if the proportioning device isn’t delivering the concentrate at the correct rate.

During post-installation testing, you want to confirm that the foam concentrate and water are being mixed in the designed ratio. Verifying proportioning accuracy does exactly that: it checks the actual foam solution concentration at the discharge against the specified design percentage (for example, 3% or 6%). When this ratio is confirmed correct, the foam solution will have the intended properties and performance for fire control.

Other checks, like color coding or verifying that there is no leakage, relate to documentation or system integrity, and while important, do not prove that the foam concentrate is being proportioned correctly. Even if the discharge rate matches an expected value, the concentration could still be off if the proportioning device isn’t delivering the concentrate at the correct rate.