What is the maximum temperature of any water discharging into any part of the drainage system?

What is the maximum temperature of any water discharging into any part of the drainage system?

• A. 120 degrees F
• B. 180 degrees F
• C. 140 degrees F
• D. 160 degrees F

Answer: (B)

The principle here is safety and material compatibility of the drainage system when hot water enters it. Plumbing codes set a limit on how hot water that discharges into the drainage system can be, to protect piping, joints, gaskets, and traps from heat damage and to avoid problems from excessively hot water entering the waste system. 180°F is the temperature cap used in practice because it represents the upper bound that most drainage components are designed to tolerate for short-term hot-water discharge (such as from a water heater relief valve) without being damaged. Water hotter than this could soften plastics, degrade seals, or stress fittings. The other temperatures are not the standard limit for drainage. Domestic hot water safety often targets lower temps for use in fixtures (to prevent scalding), but the drainage system itself has this 180°F maximum as the code-required limit for anything discharging into it.

The principle here is safety and material compatibility of the drainage system when hot water enters it. Plumbing codes set a limit on how hot water that discharges into the drainage system can be, to protect piping, joints, gaskets, and traps from heat damage and to avoid problems from excessively hot water entering the waste system.

180°F is the temperature cap used in practice because it represents the upper bound that most drainage components are designed to tolerate for short-term hot-water discharge (such as from a water heater relief valve) without being damaged. Water hotter than this could soften plastics, degrade seals, or stress fittings.

The other temperatures are not the standard limit for drainage. Domestic hot water safety often targets lower temps for use in fixtures (to prevent scalding), but the drainage system itself has this 180°F maximum as the code-required limit for anything discharging into it.