Which of the following appliances would typically utilize a Single Acting type Draft Regulator?

A Single Acting type Draft Regulator is primarily used in systems where the draft needs to be maintained at a relatively constant level to ensure efficient combustion. This type of regulator is designed to open or close in response to variations in draft pressure, allowing for more precise control in applications that need a steady draft.

In the context of the provided options, an incinerator is indeed an appliance that would typically utilize a Single Acting type Draft Regulator. Incinerators require careful management of draft to ensure complete combustion of waste materials and to control emissions. The design and operation of incinerators often demand a consistent draft to maintain optimal burning conditions, making the Single Acting type Draft Regulator particularly suitable.

On the other hand, appliances like water heaters, furnaces, and boilers may use different types of draft control mechanisms, including varying pressure requirements and operational conditions that are not as conducive to a Single Acting regulator's specific function of constant draft maintenance. These appliances may involve more complex demands regarding airflow and pressure regulation that a Single Acting type Draft Regulator may not be designed to handle effectively.