A vacuum induction proportioning system does what to the pressure in the foam concentrate proportioning inlet tube relative to the system flow passageway?

A vacuum induction proportioning system does what to the pressure in the foam concentrate proportioning inlet tube relative to the system flow passageway?

• A. Increases
• B. Maintains
• C. Decreases
• D. Fluctuates

Answer: (C)

Vacuum induction systems create suction by lowering the pressure in the foam concentrate inlet line below the pressure of the main system flow. As water moves through the flow passage, the velocity increases and static pressure drops (Venturi effect). This negative pressure in the concentrate inlet draws foam concentrate into the stream. So the pressure in the foam concentrate inlet tube relative to the system flow passageway decreases. If the pressure were to rise or stay the same, suction would be lost and proportioning would fail; the design relies on maintaining a lower pressure to pull the concentrate consistently.

Vacuum induction systems create suction by lowering the pressure in the foam concentrate inlet line below the pressure of the main system flow. As water moves through the flow passage, the velocity increases and static pressure drops (Venturi effect). This negative pressure in the concentrate inlet draws foam concentrate into the stream. So the pressure in the foam concentrate inlet tube relative to the system flow passageway decreases. If the pressure were to rise or stay the same, suction would be lost and proportioning would fail; the design relies on maintaining a lower pressure to pull the concentrate consistently.