What is a common type of device used in a commercial ice machine?

In a commercial ice machine, a dual check valve is commonly used to prevent backflow from the ice machine back into the water supply. This is crucial in maintaining the safety and quality of the water being supplied to the ice machine. The dual check valve consists of two check valves that work together to provide an additional level of protection against back siphonage or backflow conditions, ensuring that potentially contaminated water does not mix with the potable water supply.

This safeguard is particularly important in commercial applications where any contamination could impact numerous consumers. By effectively isolating the ice machine from the municipal water supply, the dual check valve plays a vital role in maintaining hygienic conditions and compliance with health ordinances.

Other devices listed, while essential in different contexts, do not specifically serve the function of preventing backflow in the same way that a dual check valve does. Therefore, the dual check valve is the most appropriate choice for ensuring the safety of the water supply in a commercial ice machine.