Question 205Steam Plants - Assistant Engineer

The correct answer is D) mica shield. The glass used in a flat-type boiler water gage is protected from the hot steam and water by a mica shield. Mica is a mineral material that is heat-resistant and can withstand the high temperatures and pressures encountered in a boiler environment. The mica shield acts as a protective barrier, preventing the hot steam and water from directly contacting the glass, which could otherwise cause damage or cracking. The other options are incorrect because they do not provide the necessary protection for the boiler water gage glass. Asbestos gaskets, copper insulators, and felt cushions are not specifically designed to withstand the harsh conditions inside a boiler and would not be suitable for this application.