What is the purpose of casing seals?

• A. To prevent leakage to atmosphere where rotor penetrates the casing
• B. To seal lubricant inside housings
• C. To prevent oil leaks into discharge line
• D. To prevent moisture from entering

Answer: (A)

The essential idea is that casing seals form a barrier where the rotor passes through the housing to keep the process fluid contained and prevent it from leaking to the outside environment. This shaft penetration is a potential leakage path, so the seal stops hydrocarbons or other fluids from escaping to the atmosphere, protecting people, the environment, and reducing emissions. While seals also help limit lubricant leakage, the primary purpose is to prevent leakage to the atmosphere at the shaft interface.