Device '27' shown in the illustration is used to __________. Illustration MO-0111

Correct Answer: Option C — regulate maximum vacuum during normal operation

Device '27' functions as a vacuum regulator or air-bleed valve. By controlling the amount of non-condensable gases removed or allowing controlled air ingress, it maintains the evaporator's vacuum within the optimal design range, preventing excessive vacuum that could lead to boiling instability or equipment damage.