When turbine rotor shafts extend through the...

Question 1 / 2707066636ef128f7522a1c521a92

Question 1 of 2707066636ef128f7522a1c521a92

When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjunction with labyrinth packing to __________.

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Question 1 of 27070

When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjunction with labyrinth packing to __________.

🔍 Key Concepts

• Labyrinth packing purpose on turbine rotor shafts • Role of sealing steam when shaft penetrates a casing with different internal vs external pressures • Effect of high vs low casing pressure on steam leakage direction (into vs out of the casing)

💭 Think About

• Think about what naturally happens at the shaft if the pressure inside the casing is lower than the surrounding pressure versus when it is higher. Which way does steam/air want to flow? • What is the main job of sealing steam around a rotating shaft – is it about temperature control, condensate flow, or controlling leakage and air in-leakage? • If you already have high casing pressure, do you really need an external sealing steam source to keep steam from escaping, or is the external source more important when the turbine pressure is lower than its surroundings?

✅ Before You Answer

• Be clear on the direction of leakage flow: from high pressure to low pressure. • Decide whether sealing steam is mainly to prevent air from entering the casing or steam from leaving the casing. • Check which choice actually describes a pressure condition where an additional external sealing steam source would be necessary to assist the labyrinth packing.

Question 1 of 27070

When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjunction with labyrinth packing to __________.

seal the casing during periods of high casing pressure

provide a constant flow to the gland leakoff condenser

seal the casing during periods of low casing pressure

maintain the rotor journal temperature

Question 1 / 2707066636ef128f7522a1c521a92

Question 1 of 2707066636ef128f7522a1c521a92

When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjunction with labyrinth packing to __________.

Back

Question 1 of 27070

When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjunction with labyrinth packing to __________.