Water Supply & Distribution Systems Flashcards

What is the minimum water pressure required at the point of use for most plumbing fixtures per the Uniform Plumbing Code?

Answer: 20 psi

The Uniform Plumbing Code requires a minimum of 20 psi at the point of use for most fixtures to ensure adequate flow.

Which type of pipe material is most resistant to dezincification in water supply systems?

Answer: Dezincification-resistant (DZR) brass

DZR brass alloys are specifically formulated with inhibitors to resist dezincification in aggressive water conditions.

In a zone-pressure distribution system for a tall building, what is the typical maximum zone height to limit static pressure?

Answer: 10 floors

Zones are typically limited to approximately 10 floors (about 100 ft) to keep static pressure within acceptable limits of around 45 psi.

What ASTM standard covers copper water tube Type L used in plumbing systems?

Answer: ASTM B88

ASTM B88 is the standard specification for seamless copper water tube, covering Types K, L, and M.

Which method is used to calculate the design flow rate in a water distribution system based on fixture unit values?

Answer: Hunter's curve method

Hunter's curve (Hunter's method) converts water supply fixture units (WSFU) into probable simultaneous flow rates (gpm).

A recirculating hot water system is designed primarily to:

Answer: Deliver hot water quickly and reduce waste

Recirculating systems keep hot water circulating through the distribution loop so it arrives quickly at fixtures, reducing both wait time and water waste.

What is the purpose of a vacuum breaker on a hose bibb connection?

Answer: To prevent backflow by siphonage

A vacuum breaker on a hose bibb prevents backflow by breaking the siphon if the supply pressure drops below atmospheric pressure.