Journeyman Plumber ExamPlumbing Code and RegulationsMedium
A plumber is installing a water-hammer arrestor on a washing machine supply line. According to the Uniform Plumbing Code (UPC), where should water-hammer arrestors be installed?
- AOn the main water supply line entering the building.
- BAt the highest point in the plumbing system to release air.
- COnly on hot water lines to prevent scalding.
- DAt each fixture or appliance where quick-closing valves are used.
Show answer & explanationAnswer & explanation
Correct answer: D. At each fixture or appliance where quick-closing valves are used.
Water-hammer arrestors are specifically required at each fixture or appliance where a quick-closing valve is installed. This prevents the sudden pressure surge (water hammer) that occurs when these valves rapidly stop water flow, protecting the plumbing system from damage and noise.
Why the other options are wrong
- A. While a main line arrestor might help generally, the code specifically requires them at points of origin for water hammer.
- B. Releasing air is the function of an air vent, not a water-hammer arrestor.
- C. Water hammer can occur on both hot and cold lines, and its purpose is not related to scalding prevention.
Water Hammer Arrestor Placement
The required location for installing devices that absorb pressure surges caused by sudden valve closures in a plumbing system.
- Prevents noise and pipe damage.
- Required for quick-closing valves.
- Installation location is critical for effectiveness.
Memory trick: Quick valve close, a hammer's blow, an arrestor near, makes quiet flow.