What is the primary function of a flush tank?

The primary function of a flush tank is to flush the contents of a toilet fixture. In a typical toilet setup, the flush tank is filled with water, which is then released all at once when the flush mechanism is engaged. This sudden release of water creates sufficient force to wash away waste and refill the toilet bowl. The design ensures that ample water volume is rapidly available to effectively clear the bowl and maintain hygiene.

In this context, other options do not capture the primary purpose of a flush tank. While some tanks may store water, like in the case of rainwater collection systems, that is not their function in a toilet context. Additionally, flush tanks are not designed to provide pressure to shower systems; that function is generally handled by water supply systems and valves. Finally, capturing rainwater represents a different aspect of plumbing entirely, focusing on water conservation rather than the flushing mechanism of toilets.