What fixture unit load does each gallon per minute (GPM) of a continuous flow pump or similar fixture produce?

Each gallon per minute (GPM) of a continuous flow pump or similar fixture produces 2 fixture units (FU). This standard reflects the hydraulic demands placed on a plumbing system by continuous flow fixtures, which require consistent water supply and drainage capabilities.

The designation of 2 fixture units per gallon per minute acknowledges both the flow rate and the potential impact on the plumbing system's overall performance. Fixture units are a key metric in plumbing design as they provide a way to calculate the total expected demand from multiple fixtures, allowing for proper sizing of pipes and equipment. Continuous flow fixtures are typically considered to have a higher demand due to their unceasing operation, which is why they are rated at this higher fixture unit value compared to intermittent or static fixtures that would produce a different load.