Question 350Motor Plants - Assistant Engineer

The correct answer is C) regulate maximum vacuum during normal operation. The device "27" shown in the illustration is likely a vacuum regulator, which is used to control and limit the maximum vacuum level in the system. This is an important safety feature to prevent excessive vacuum conditions that could damage equipment or pose a hazard. The other answer choices are incorrect because: A) purging non-condensable gases is typically done by a different mechanism, B) adding descaling chemicals is not the function of this particular device, and D) relieving excess pressure is typically done by a pressure relief valve, not the vacuum regulator.