What is the purpose of a vacuum breaker in a steam system?

A vacuum breaker is an essential component in a steam system, specifically designed to prevent backflow and safeguard the integrity of the system against collapse. When steam is used in a system, it operates under high pressure; however, if the steam condenses, it can create a vacuum. This vacuum can lead to backflow of condensate into the steam lines, potentially causing water hammer or damage to equipment.

The vacuum breaker allows air to enter the system when a vacuum condition is detected. By equalizing the pressure, it prevents backflow of liquid and protects against the collapse of pipes and other components that could be compromised under negative pressure. This is crucial for maintaining safe and efficient operation in steam systems.

The other options do not accurately describe the function of a vacuum breaker. Increasing steam pressure is not within the purview of a vacuum breaker, nor does it dry the steam or regulate the temperature. Its primary role is focused on maintaining the pressure balance and protecting the integrity of the system through the prevention of unwanted backflow and vacuum conditions.