Question 585Steam Plants - Assistant Engineer

The correct answer is C) cold air rapidly entering the gland may result in damage to the carbon segments and sealing surfaces. The reasoning behind this is that when securing a main propulsion turbine equipped with carbon packing glands, it's crucial to break the vacuum before securing the gland seal steam. This is because rapidly introducing cold air into the gland area can cause thermal shock and damage to the delicate carbon segments and sealing surfaces. Allowing the gland to cool gradually helps prevent this potential damage. The other options are incorrect because they do not address the primary concern of avoiding thermal shock to the turbine gland components.