Journeyman Plumber ExamFixtures, Faucets, and Other AppliancesMedium

A client is replacing an existing electric water heater. The new water heater has a capacity of 50 gallons. According to common plumbing practices and code, what is the maximum length allowed for the temperature and pressure (T&P) relief valve discharge pipe?

  1. A10 feet
  2. B5 feet
  3. C15 feet
  4. DNo specific maximum length, as long as it's pitched correctly.
Show answer & explanation

Correct answer: D. No specific maximum length, as long as it's pitched correctly.

Plumbing codes, such as the IPC and UPC, do not specify a maximum length for the T&P relief valve discharge pipe. The critical requirements are that it must be properly sized, pitched for drainage, terminate in a safe location, and not be trapped or have any valves.

Why the other options are wrong

  • A. 10 feet is not a code-specified maximum length for a T&P discharge pipe.
  • B. 5 feet is not a code-specified maximum length for a T&P discharge pipe.
  • C. 15 feet is not a code-specified maximum length for a T&P discharge pipe.

T&P Discharge Pipe Length

The length of the discharge pipe from a T&P relief valve is not typically restricted by a maximum numerical value in plumbing codes.

  • Must be full size of valve outlet.
  • Must terminate in a safe, visible location.
  • Must be continuously downward sloping.
  • No valves or obstructions allowed.

Memory trick: Safety first, length second, flow always.

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