What are throttling losses and how do they impact system performance?

• A. Throttling increases flow, reduces resistance.
• B. Throttling restricts flow, causing a pressure drop and energy loss as heat, reducing actuator speed and increasing energy consumption.
• C. Throttling has no effect on energy consumption.
• D. Throttling converts hydraulic energy to electrical power.

Answer: (B)

Throttling losses come from forcing fluid through a restriction, like a valve or small orifice. When flow passes this restriction, a large pressure drop develops across it. The energy difference between upstream and downstream is not used to do useful work downstream; it is dissipated as heat due to friction and turbulence inside the fluid and on the walls. That means less pressure and/or flow reaches the actuator, so it moves more slowly. To maintain the same performance, the pump has to work harder to overcome the extra drop, which increases energy consumption. This is why throttling reduces efficiency and slows actuation.

The other options don’t fit because throttling doesn’t increase flow; it creates a restriction. It does affect energy use by dissipating energy as heat, not leaving energy unchanged. And it doesn’t convert hydraulic energy into electrical power.