Oilers/Plant Tenders (HHC) Civil Service Practice Exam

In which application is labyrinth packing commonly used?

1. Diesel engines

2. Steam-turbines

3. Piston pumps

4. Hydraulic systems

The correct answer is: Steam-turbines

Labyrinth packing is commonly used in steam-turbines due to its unique capability to control leakage while allowing for relative movement between components. This type of packing is designed to create a series of narrow passages, or "labyrinths," that provide resistance to the flow of steam or fluid. In steam-turbines, maintaining pressure and minimizing steam loss is crucial for efficient operation. The labyrinth design effectively reduces the amount of steam escaping from the turbine casing while still permitting the necessary thermal expansion and movement of the turbine shaft. The durability and ability of labyrinth packing to withstand high temperatures and pressures make it particularly suitable for this application. Other applications like diesel engines and hydraulic systems may involve different sealing needs, such as more robust sealing against liquids or gases, which is why labyrinth packing is not typically favored in those contexts. Similarly, piston pumps may require specific seals that can accommodate reciprocating motion and high pressures, making labyrinth packing less applicable.