What problem does the seal oil tank help overcome?

• A. Gas pressure at the compressor height
• B. High humidity in the environment
• C. Oil foaming in the lube oil tank
• D. Thermal expansion of seals

Answer: (A)

The main idea is that the seal oil tank creates a stable oil head that provides backpressure to the mechanical seal, helping to resist the high gas pressure at the compressor discharge. By maintaining a controlled column of oil, the seal oil system keeps a barrier at the seal faces, so process gas doesn’t push into the oil side or cause leakage along the shaft. This backpressure helps ensure the seal stays lubricated and cool while preventing gas migration into the lube oil circuit.

Humidity, foaming, and thermal expansion aren’t the primary roles of the seal oil tank. Humidity control is handled by environmental and filtration aspects, foaming is addressed by proper oil management and separation in the system, and thermal expansion is mitigated through overall design and expansion considerations rather than the tank’s main function.