Which of the following statements represents the proper procedural sequence for adjusting the metering rate of an in-line lubricator as used in a ship's service air system hose station? Assume that the pressure regulator has been properly set.

Correct Answer: Option A — Establish normal air flow. Determine drip rate. Further open needle valve to increase drip rate or further close needle valve to decrease drip rate, as appropriate.

Metering rates for in-line lubricators must be adjusted while the system is under normal operating airflow. The venturi effect within the lubricator relies on air velocity to draw oil into the stream. Adjusting the needle valve while the air is flowing allows for immediate, accurate observation of the drip rate.