What does pressure loss in a hydraulic line primarily depend on?

Pressure loss in a hydraulic line is primarily influenced by flow velocity because it is directly linked to the kinetic energy of the fluid moving through the system. When flow velocity increases, the friction between the fluid and the walls of the pipe also increases, leading to greater pressure losses. This is governed by the principles of fluid dynamics, particularly through the Darcy-Weisbach equation and the concept of head loss due to friction.

While other factors like pipe diameter, fluid temperature, and fluid viscosity also play significant roles in pressure loss, flow velocity is the primary factor because it has a squared relationship with the pressure loss in many situations. As flow velocity increases, the impact on pressure losses becomes more pronounced, making this the most critical variable in determining how much pressure is lost in a hydraulic line.