During visual inspection of foam concentrate strainers, which condition must be verified?

• A. Blowdown valve is open
• B. Blowdown valve is closed and plugged
• C. Strainer is absent
• D. Tank is pressurized

Answer: (B)

During visual inspection of foam concentrate strainers, the line must be isolated so you can accurately assess the strainer without interference. The blowdown valve should be closed and plugged to prevent any bypass or discharge through the blowdown line while you inspect, and to keep the system sealed. If the valve were left open, contaminants could bypass the strainer or concentrate could leak, making it impossible to verify the strainer’s condition. The other conditions aren’t part of this inspection: having the strainer absent means there’s no filtration at all, and the tank being pressurized isn’t a direct indicator of the strainer’s integrity. Therefore, the required state is that the blowdown valve is closed and plugged.