CSLB C-46 Solar ContractorElectrical and Plumbing CodesHard
A solar contractor is installing a new solar water heating system for a residential application. The system uses a potable water storage tank and includes a temperature and pressure (T&P) relief valve. According to the California Plumbing Code (CPC), the discharge pipe from the T&P relief valve must be installed to allow complete visual inspection of the flow. What is the maximum height above the receptor to which the discharge pipe can terminate?
- A6 inches (150 mm)
- B4 inches (100 mm)
- C8 inches (200 mm)
- D2 inches (50 mm)
Show answer & explanationAnswer & explanation
Correct answer: A. 6 inches (150 mm)
CPC Section 504.6.4 (UPC 504.6.4) specifies that the discharge pipe from a T&P relief valve shall terminate not more than 6 inches (150 mm) above the floor or flood level rim of the receptor, to allow for complete visual inspection of any discharge. This ensures that a leaking or active T&P valve is easily noticeable.
Why the other options are wrong
- B. 4 inches is too low and not the specified maximum.
- C. 8 inches is too high and would not meet the code requirement for visual inspection.
- D. 2 inches is too low and not the specified maximum.
T&P Discharge Pipe Termination Height
CPC Section 504.6.4 mandates that a T&P relief valve discharge pipe terminate not more than 6 inches above the receptor for visual inspection.
- Ensures early detection of valve activation.
- Prevents water damage from hidden leaks.
- Applies to potable water heater systems.
Memory trick: T&P Discharge: Six Inches Max for a Clear View.