Journeyman Plumber ExamWater Supply SystemsMedium
A plumber is installing a water distribution system for a small office building. The system includes a water softener and a hot water heater. To prevent the softened water from mixing with the cold water supply used for drinking fountains and toilets before the softener, where should the cold water branch for these fixtures ideally be taken off the main supply?
- ABefore the water softener.
- BImmediately after the water heater.
- CImmediately after the water softener.
- DAfter the main shut-off valve, but before any other devices.
Show answer & explanationAnswer & explanation
Correct answer: A. Before the water softener.
To ensure that non-softened water is supplied to fixtures like drinking fountains and toilets (which do not require softened water and may even benefit from unsoftened water to prevent certain issues), the cold water branch for these fixtures should be taken off the main supply line before it reaches the water softener.
Why the other options are wrong
- B. Taking the branch after the water heater would only provide hot, softened water, which is incorrect for cold drinking water.
- C. Taking the branch after the water softener would mean all cold water to these fixtures is softened, which is not the ideal setup.
- D. While after the main shut-off is correct for the overall system, 'before any other devices' is too general. The key is specifically 'before the water softener' for unsoftened cold water.
Water Softener Bypass Piping
The plumbing configuration around a water softener that allows certain cold water lines to bypass the softening process, providing unsoftened water to specific fixtures.
- Commonly used for outdoor hose bibs, drinking water, and sometimes toilets.
- Prevents unnecessary use of softened water.
- Ensures proper water quality for specific applications.
Memory trick: For fresh, unsoftened sip, bypass the softener, make the trip.