Practice question

During discharge line preparation, what is the purpose of priming before charging?

  1. To increase the line's air content.
  2. To shorten the time needed to connect hoses.
  3. To reduce the need for a spotter.
  4. To maintain stable flow and prevent surging.

Answer: A — To increase the line's air content.

Priming the discharge line before charging aims to remove air from the line and fill it with water so there’s a continuous water column when flow starts. This keeps the discharge flow steady and reduces the risk of surges or water hammer as the line is charged and the nozzle is opened. In other words, priming helps maintain stable flow rather than increasing air content or affecting hose connection time or spotter needs.

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