Question 58 QMED03 - Oiler

The Correct Answer is A **Explanation for Option A (Correct):** Try-cocks (or gauge cocks) are small valves installed directly onto the boiler shell or water column, usually in a set of three, positioned above, at, and below the normal operating water level. Their primary function is to serve as a backup mechanism for confirming the boiler's water level. If the primary water level indicator (the gauge glass) breaks, becomes dirty, or otherwise malfunctions, the operator can open the try-cocks. If steam issues from the top cock, water from the bottom cock, and a mixture of steam and water from the middle cock, the operator can confirm that the water level is within the safe operating limits, providing an essential safety check until the gauge glass can be repaired. **Why Options B, C, and D are Incorrect:** * **B) provide a means of adding chemical feed to the boiler water:** Chemical feed is typically introduced via dedicated chemical dosing pumps and injection ports, not through the try-cocks, which are purely for level indication. * **C) provide a means for blowing down the gage glass:** Blowing down (cleaning out) the gauge glass is performed using dedicated drain valves connected directly to the gauge glass assembly, not the try-cocks. * **D) act as a steam sentinel valve, if any of the fusible plugs should melt:** Try-cocks have no relationship to fusible plugs or sentinel valves. Fusible plugs are safety devices that melt if the water level drops dangerously low, allowing steam to escape into the furnace to warn the operator. Sentinel valves are often simple warning whistles attached to high-pressure lines.