Question 614Steam Plants - Assistant Engineer

The correct answer is B) precision metal-to-metal contact. The turbine casing is designed to have a precise metal-to-metal fit between the upper and lower halves. This metal-to-metal contact creates an efficient seal that prevents leaks and maintains the proper pressure and temperature within the turbine. Gaskets, such as asbestos, copper, or flexible steel, are not typically used for the primary sealing mechanism in turbine casings, as they can degrade over time and lose their sealing ability. The precision machining of the mating surfaces is the most reliable and long-lasting method for creating an efficient seal in a turbine casing.