BOC BOC Plumbing and Water Systems

Question 1

What is the primary purpose of a backflow preventer in a building's plumbing system?

Accepted Answer

To prevent contaminated water from flowing back into the potable water supply

Answer

To increase water pressure

Answer

To reduce water hammer

Answer

To filter sediment from incoming water

Question 2

Which type of water heater is typically most energy-efficient for commercial buildings with high and consistent hot water demand?

Accepted Answer

Condensing boiler-based indirect water heater

Answer

Tank-type electric water heater

Answer

Tankless point-of-use heater

Answer

Heat pump water heater

Question 3

What does a pressure-reducing valve (PRV) do in a building water system?

Accepted Answer

Steps down high street main pressure to a safe working pressure inside the building

Answer

Boosts incoming water pressure to upper floors

Answer

Prevents water hammer in supply lines

Answer

Regulates flow rate to individual fixtures

Question 4

Which test is used to check a sanitary drain system for leaks before walls are closed during construction or renovation?

Accepted Answer

Hydrostatic pressure test

Answer

Air pressure test

Answer

Smoke test

Answer

Ball test

Question 5

In a building's domestic hot water system, what is the purpose of a recirculation loop?

Accepted Answer

To ensure hot water is quickly available at fixtures without long wait times

Answer

To increase water heater capacity

Answer

To reduce incoming cold water pressure

Answer

To allow dual-temperature zones

Question 6

What type of valve should be installed as the main water shut-off for a building to allow full flow with minimal pressure loss?

Accepted Answer

Gate valve or full-port ball valve

Answer

Globe valve

Answer

Check valve

Answer

Butterfly valve