Air break devices must be incorporated in which of the following?

Air break devices are crucial in plumbing systems as they prevent wastewater from flowing back into potable water supplies. They create a physical separation between the potable water and the wastewater, ensuring that contaminants do not enter the drinking water system.

Clothes washing devices require air break devices because they often drain into a standpipe or a sink and have the potential to create back pressure, which could lead to wastewater siphoning back into the machine. An air break allows proper drainage while maintaining a safe barrier to prevent any possible contamination of the water supply.

In contrast, while water heaters, bathroom toilets, and kitchen sinks may also involve drainage and plumbing considerations, the specific requirement for air break devices is particularly associated with the design and function of clothes washing devices due to their wastewater discharge mechanisms and the risk of backflow during operation.