What other device must be installed to protect an element when it is automatically controlled?

The installation of a vacuum breaker is critical in scenarios where elements are automatically controlled, particularly in systems that can experience negative pressure or siphoning conditions. A vacuum breaker serves as a safety device designed to prevent backflow, which can occur if a system experiences a drop in pressure. This backflow could lead to contamination of the supply water or damage to the equipment due to the suction created by negative pressure.

In various applications, such as water heating or cooling systems, maintaining a consistent flow of the fluid (water, steam, etc.) is essential for operational efficiency and safety. When an automated control system manages these flows, the potential for unexpected pressure changes increases, necessitating the protective function of a vacuum breaker. It ensures that if a negative pressure situation arises, air enters the system and alleviates the vacuum, thereby preventing the harmful effects that could compromise the integrity of the system or expose it to contaminants.

Other options like a flow restrictor, pressure gauge, and filter screen serve different functions. A flow restrictor limits the flow rate but doesn't prevent negative pressure. A pressure gauge provides information about the pressure within a system, but does not offer protection against backflow. A filter screen prevents debris from entering the system, contributing to system longevity,