What components must water closet tanks contain?

Water closet tanks must contain specific components to function efficiently and comply with plumbing standards. The correct answer includes a 1.6 gallons per flush (gpf) mechanism, an anti-siphon ball cock, and a refill tube.

The 1.6 gpf mechanism is essential because it ensures efficient water usage while effectively flushing waste. This standard was established to promote water conservation in bathroom fixtures. An anti-siphon ball cock is critical for preventing backflow of contaminated water into the potable water supply, helping maintain water quality and safety. The refill tube's role is to direct water into the overflow tube after the flush, ensuring that the tank fills correctly without creating leaks or overflowing.

These components work together to ensure that the toilet operates effectively and adheres to modern plumbing codes designed to protect public health and conserve water. The combination of efficiency, safety, and proper water management makes this selection the most accurate for the requirements of water closet tanks.