Which symptom indicates heat damage has occurred to a hose?

• A. Jacket scoured with no effect to lining
• B. Lining becomes more flexible
• C. Jacket scorched; lining burns, hardens, and cracks
• D. Fittings corrode rapidly

Answer: (C)

Heat damage shows up when the hose materials have been exposed to excessive heat, causing the outer jacket to scorch and the inner lining to burn, stiffen, and crack. This combination is a clear sign that the hose has suffered thermal degradation—the scorching on the jacket is the visible clue of heat exposure, and the lining’s burning and hardening indicate internal damage that compromises the hose’s integrity. Other signs point to different issues: scoured jacket with no effect on the lining suggests surface wear rather than heat; the lining becoming more flexible would imply softening from something like chemical exposure rather than heat-induced brittleness; and rapid corrosion of fittings indicates metal reaction, not heat damage to the hose material itself.