What is typically included in a backflow preventer assembly?

A backflow preventer assembly is designed to protect potable water supplies from contamination due to backflow. This assembly typically includes check valves, which are critical components that allow water to flow in one direction only and prevent reverse flow. Differential valves may also be part of the assembly, regulating pressure differences in the system to ensure that water does not flow back into the supply line.

The inclusion of these components in the backflow preventer assembly plays a vital role in maintaining safe water quality. Check valves ensure that any drop in water pressure or back siphonage does not allow contaminants from non-potable sources to enter the drinking water supply.

In contrast, the other answer choices do not accurately represent the purpose or components of a backflow preventer assembly. Heat regulation valves and pressure control valves, for instance, are used in different plumbing systems for temperature and pressure management but are not essential for backflow prevention. Flow measurement devices and pressure gauges are tools for monitoring system performance rather than preventing backflow. Similarly, filtering systems and sterilization units serve to purify water but do not function to prevent backflow. Therefore, the inclusion of check valves and potentially differential valves accurately characterizes the necessary components of a backflow preventer assembly.