Which hydraulic system includes a stand pipe in the reservoir?

• A. System D
• B. System B
• C. System A
• D. System C

Answer: (A)

A stand pipe in a hydraulic reservoir keeps the pump’s suction leg fed with fluid even as the reservoir level changes, which helps prevent cavitation and keeps the system primed. The stand pipe extends from the bottom toward the top, forming an internal path for fluid to the pump while the space above it vents air. This arrangement ensures the pump consistently draws from submerged fluid, maintaining a stable suction head during high demand or attitude changes.

In System D, the reservoir is designed with this stand pipe, so it specifically includes that feature. The other systems don’t incorporate a stand pipe in their reservoir designs, so they don’t provide that guaranteed submerged suction path.