Which device would be considered a continuous-flow device for drainage fixture unit calculations?

• A. Sink
• B. Toilet
• C. Pump
• D. Faucet

Answer: (C)

In drainage fixture unit calculations, the key idea is whether a device discharges waste into the drainage system for a continuous period or only in short bursts. A pump is designed to move wastewater into the drain continuously while it’s running, so it’s treated as a continuous-flow device. Sinks, toilets, and faucets discharge during use and stop fairly quickly, so they’re regarded as intermittent-flow fixtures. That’s why the pump is the continuous-flow choice.