The purpose of try-cocks used on an auxiliary boiler is to __________.

Correct Answer: Option A — provide an alternate means of determining the water level, if the gage glass fails

Try-cocks are mandatory redundant water-level indicators on auxiliary boilers. If the primary gauge glass becomes obscured or fails, the operator can manually open the try-cocks to determine the water level by observing whether steam or water discharges, ensuring safe boiler operation and preventing low-water conditions that could cause catastrophic damage.