Question 655Steam Plants - Assistant Engineer

The correct answer is C) moisture in the turbine steam. Packing rings installed on auxiliary turbines are generally lubricated by the moisture present in the turbine steam. The steam passing through the turbine provides the necessary lubrication for the packing rings, which helps to create a tight seal and prevent steam leakage. This is a common design feature in turbine-driven auxiliary equipment, as it eliminates the need for a separate lubrication system. The other options are incorrect because: A) separate lube oil lines are not used to lubricate packing rings, as the steam provides the necessary lubrication; B) a water leak-off line is not used for this purpose; and D) a salt water service line would not be appropriate for lubricating packing rings in an auxiliary turbine.