IPC - International Plumbing Code Water Supply and Distribution 2

Question 1

According to the IPC, which of the following pipe materials is NOT permitted for use in potable water distribution systems inside a building?

Accepted Answer

Lead pipe

Answer

The IPC expressly prohibits lead pipe in potable water systems due to its well-documented health hazards. Copper Type L, PEX, and CPVC are all listed approved materials for interior potable water distribution.

Question 2

The IPC requires a pressure-reducing valve (PRV) to be installed when the building water pressure exceeds a certain threshold. What is that threshold?

Accepted Answer

80 psi

Answer

IPC Section 604.8 requires a pressure-reducing valve whenever the static water pressure supplied to a building exceeds 80 psi, to protect fixtures and piping from excessive pressure.

Question 3

Under the IPC, what type of device must be installed on the water supply line serving a hose bibb (outdoor hose connection) to protect the potable water supply?

Accepted Answer

Atmospheric vacuum breaker

Answer

The IPC requires an atmospheric vacuum breaker (or equivalent backflow preventer) on hose bibbs because a garden hose submerged in a bucket or chemical solution can back-siphon contaminants into the potable supply. An atmospheric vacuum breaker is the standard protection at this type of connection.

Question 4

According to the IPC, what is the minimum pressure that must be maintained at every fixture in a building's water distribution system during peak demand?

Accepted Answer

15 psi

Answer

IPC Section 604.3 sets 15 psi as the minimum flow pressure required at every plumbing fixture. Pressure below this threshold results in inadequate flow and potential backflow conditions.

Question 5

When sizing a water distribution system, the IPC uses fixture units to estimate demand load. What term describes the method used in the IPC for converting fixture unit counts into pipe size?

Accepted Answer

Hunter's Curve method

Answer

The IPC's pipe-sizing tables and demand-load conversion charts are based on Hunter's Curve (the Roy B. Hunter method), which correlates fixture unit totals to probable peak flow rates for sizing distribution piping.

IPC - International Plumbing Code Practice Test

IPC - International Plumbing Code Practice Test

IPC - International Plumbing Code Water Supply and Distribution 2