306A Water Supply Systems 1 — Questions and Answers
Question 1: What is the minimum hot water supply temperature at a residential fixture outlet according to Canadian plumbing standards?
- 38°C
- 43°C (Correct answer)
- 49°C
- 60°C
Correct answer: 43°C
The minimum hot water temperature at a residential fixture outlet is 43°C (110°F) to ensure adequate hot water delivery while balancing scald prevention.
Question 2: What is the minimum water pressure required at a fixture outlet for proper operation?
- 69 kPa (10 psi)
- 103 kPa (15 psi)
- 140 kPa (20 psi) (Correct answer)
- 207 kPa (30 psi)
Correct answer: 140 kPa (20 psi)
A minimum of 140 kPa (20 psi) is required at the most remote fixture outlet to ensure adequate flow for proper fixture operation.
Question 3: What is the maximum static water pressure permitted at a fixture outlet?
- 345 kPa (50 psi)
- 414 kPa (60 psi)
- 552 kPa (80 psi) (Correct answer)
- 689 kPa (100 psi)
Correct answer: 552 kPa (80 psi)
The maximum static pressure at a fixture outlet is 552 kPa (80 psi). A pressure-reducing valve must be installed when the supply pressure exceeds this limit to protect fixtures and piping.
Question 4: What type of valve must be installed on the water supply to each dwelling unit?
- Check valve
- Gate valve or ball valve (full-port shutoff) (Correct answer)
- Pressure-reducing valve
- Mixing valve
Correct answer: Gate valve or ball valve (full-port shutoff)
A full-port shutoff valve (gate or ball valve) is required at each dwelling unit supply so the water can be completely isolated for maintenance without affecting other units.
Question 5: What is the purpose of a water hammer arrestor in a supply system?
- To filter sediment from the water
- To reduce static pressure
- To absorb the shock wave caused by sudden valve closure (Correct answer)
- To prevent backflow
Correct answer: To absorb the shock wave caused by sudden valve closure
Water hammer arrestors contain a sealed air chamber that absorbs the pressure surge (water hammer) created when valves close suddenly, protecting pipes and fittings from damage.
Question 6: What is the minimum size of a water service pipe for a single-family dwelling?
- ½ inch
- ¾ inch (Correct answer)
- 1 inch
- 1¼ inch
Correct answer: ¾ inch
A ¾-inch water service pipe is the minimum size for a single-family dwelling, providing adequate flow for simultaneous fixture use.
306A Water Supply Systems 1
What is the minimum hot water supply temperature at a residential fixture outlet according to Canadian plumbing standards?