Journeyman Plumber ExamPlumbing Code and RegulationsMedium
A plumber is installing a water distribution system in a new home. The water supply line from the main to the house is 1-inch (25 mm) copper. According to the International Plumbing Code (IPC), what is the minimum working pressure required at the furthest fixture outlet supplied by this system, under normal operating conditions?
- A20 psi
- B8 psi
- C30 psi
- D15 psi
Show answer & explanationAnswer & explanation
Correct answer: A. 20 psi
The IPC mandates a minimum working pressure of 20 psi at the outlet of the most remotely controlled fixture. This ensures adequate flow and pressure for all fixtures and appliances throughout the building.
Why the other options are wrong
- B. 8 psi is far too low and would result in inadequate water flow and fixture operation.
- C. 30 psi would be acceptable but is not the minimum required by code.
- D. 15 psi is below the minimum required pressure for proper fixture operation.
Minimum Fixture Outlet Pressure
The lowest acceptable water pressure at the most distant fixture in a plumbing system to ensure proper function.
- Critical for fixture performance.
- Maintained under flow conditions.
- Specified by plumbing codes.
Memory trick: Twenty pounds at the farthest spout, keeps the water flowing, no doubt.