The lavatories in a public restroom are being fitted with ordinary non-metering faucets. Under the IPC maximum flow rate limits, what is the highest flow those faucets may deliver?
- A2.2 gallons per minute at 60 psi
Two and two tenths gallons per minute at 60 psi is the limit for private lavatory faucets and for sink faucets. Applying a private limit to a public fixture is the most common error on this table.
- B1.5 gallons per minute at 60 psi
One and a half gallons per minute is a widely marketed voluntary efficiency value. It is not the code maximum for this fixture, and a question that offers it is testing whether the candidate reads the table or the packaging.
- 0.5 gallon per minute at 60 psi
- D2.5 gallons per minute at 80 psi
Two and a half gallons per minute at 80 psi is the shower head maximum. Notice that both the flow and the test pressure belong to a different fixture.
Why C is correct
The maximum flow rate table in the water supply chapter lists public lavatory faucets other than metering faucets at one half gallon per minute at 60 psi. Metering faucets are governed instead by a maximum volume per metering cycle, which is why the question specifies a non-metering faucet.
What this question is testing
The item tests whether the candidate can navigate the maximum flow rate table by fixture type and reference pressure, and can distinguish public from private lavatory limits and metering from non-metering faucets.
On the job
This is a submittal review item more than a field item, but it lands in the plumber's lap because the fixture arrives, gets installed, and then fails a flow check or a green building verification. Aerators are the fix, and they are also the loophole owners use to defeat the rule, swapping in a high-flow aerator after the inspection. On restaurant and school work, expect the reviewer to check the faucet model number against this table line by line.
Memory technique
Public hands get half a gallon.
Exam tip
Every flow limit in the table comes with a test pressure. If the pressure in the option does not match the fixture, the flow is from a different row.
Where to look it up
Chapter 6, the maximum flow rates and consumption table. Several states, California most notably, adopt stricter flow limits by amendment, and UPC jurisdictions publish their own table, so verify against your adopted code.