IPC - International Plumbing Code Water Supply and Distribution Questions and Answers — Questions and Answers
Question 1: According to the IPC, what is the minimum required size for a water service pipe?
- 1/2 inch
- 5/8 inch
- 3/4 inch (Correct answer)
- 1 inch
Correct answer: 3/4 inch
IPC Section 603.1 states that the water service pipe shall be sized to supply water to the building in the quantities and at the pressures required elsewhere in the code. It specifies that the water service pipe shall not be smaller than 3/4 inch in diameter.
Question 2: A newly installed potable water distribution system must be tested for leaks. According to the IPC, what is the required test pressure if using water, and for how long must it be maintained?
- At working pressure for 10 minutes
- 50 psi above working pressure for 30 minutes
- Not less than the working pressure under which it is to be used, for 15 minutes (Correct answer)
- 100 psi for 60 minutes
Correct answer: Not less than the working pressure under which it is to be used, for 15 minutes
IPC Section 312.5 specifies the testing requirements for water supply systems. It states that upon completion, the system shall be tested and proved tight under a water pressure not less than the working pressure under which it is to be used. The water used for tests shall be obtained from a potable source of supply. The required test pressure shall be maintained for a period of not less than 15 minutes.
Question 3: In a commercial building, the static water pressure from the city main is found to be 95 psi. What action is required by the IPC?
- No action is required as this is within acceptable limits.
- Install a pressure-relief valve set at 100 psi.
- Install water hammer arrestors at all fixtures.
- Install a pressure-reducing valve to reduce the pressure to 80 psi or less. (Correct answer)
Correct answer: Install a pressure-reducing valve to reduce the pressure to 80 psi or less.
IPC Section 604.8 states that where the water pressure within a building exceeds 80 psi static, a pressure-reducing valve shall be installed to reduce the pressure to 80 psi or less. This protects fixtures and appliances from damage due to excessive pressure.
Question 4: Which of the following is an unacceptable location for a potable water service pipe according to the IPC?
- In the same trench as the building sewer, with proper separation.
- Crossing under a driveway.
- Located in, under, or above a septic tank drainage field. (Correct answer)
- Within 5 feet of an electrical grounding conductor.
Correct answer: Located in, under, or above a septic tank drainage field.
IPC Section 603.2.1 explicitly prohibits potable water service pipes from being located in, under, or above cesspools, septic tanks, septic tank drainage fields, or seepage pits to prevent contamination of the potable water supply.
Question 5: A plumber is installing a hot water storage tank in an attic where leakage could cause damage to the structure below. Which of the following is required by the IPC?
- A temperature and pressure relief valve only.
- Installation of the tank within a corrosion-resistant pan with a drain. (Correct answer)
- Seismic straps, regardless of the geographic location.
- A dedicated shutoff valve located in the living space below.
Correct answer: Installation of the tank within a corrosion-resistant pan with a drain.
IPC Section 504.7 mandates that where water heaters or hot water storage tanks are installed in locations where leakage will cause damage, the tank or water heater shall be installed in a pan. The pan must be of a corrosion-resistant material and have a drain that terminates in an approved location.
Question 6: To protect the potable water supply, a hose bibb must be protected by which of the following?
- A reduced pressure principle backflow preventer.
- A double check valve assembly.
- An atmospheric vacuum breaker or a permanently attached hose connection vacuum breaker. (Correct answer)
- A barometric loop.
Correct answer: An atmospheric vacuum breaker or a permanently attached hose connection vacuum breaker.
IPC Section 608.15.4.2 requires that hose connections, such as sill cocks and wall hydrants, be protected against backflow by an atmospheric-type vacuum breaker, a pressure-type vacuum breaker, or a permanently attached hose connection backflow preventer.
IPC - International Plumbing Code Water Supply and Distribution Questions and Answers
According to the IPC, what is the minimum required size for a water service pipe?