What is the maximum allowed length of 1 3/4 inch hose between the nozzle and the eductor?

What is the maximum allowed length of 1 3/4 inch hose between the nozzle and the eductor?

• A. 100 feet
• B. 200 feet
• C. 300 feet
• D. 400 feet

Answer: (C)

The statement tests how hose length affects an eductor’s ability to draw water and operate properly. An eductor relies on a Venturi effect, which needs a certain amount of pressure at the device to create suction and maintain the proper flow and, if applicable, foam proportioning. Running water through 1 3/4-inch hose introduces friction losses; the longer the hose, the more pressure is lost before the water reaches the eductor. If the hose is too long, the pressure at the eductor drops below what’s needed for effective operation, so you won’t get the desired flow or proportioning. With 1 3/4-inch hose, about 300 feet is the practical maximum to keep enough pressure at the eductor for reliable performance at typical pump pressures and flows. Going longer would risk inadequate suction and poor discharge performance.

The statement tests how hose length affects an eductor’s ability to draw water and operate properly. An eductor relies on a Venturi effect, which needs a certain amount of pressure at the device to create suction and maintain the proper flow and, if applicable, foam proportioning. Running water through 1 3/4-inch hose introduces friction losses; the longer the hose, the more pressure is lost before the water reaches the eductor. If the hose is too long, the pressure at the eductor drops below what’s needed for effective operation, so you won’t get the desired flow or proportioning.

With 1 3/4-inch hose, about 300 feet is the practical maximum to keep enough pressure at the eductor for reliable performance at typical pump pressures and flows. Going longer would risk inadequate suction and poor discharge performance.