Incorrect hose diameter selection is one of the most common mistakes in the construction and modernization of hydraulic systems. A hose that is too narrow leads to a rapid increase in flow velocity, resulting in turbulence, drastic oil heating, and significant pressure losses.
With our calculator, you can select the optimal internal hose diameter in seconds.
Hydraulic Hose Diameter Selection Calculator
Calculate the optimal internal hose diameter based on flow rate and line type.
Why is the internal diameter of the hose crucial?
In power hydraulics, it's not the external diameter of the hose that matters, but its internal cross-section (DN). This determines whether the oil flows freely (laminar flow) or starts to generate resistance (turbulent flow).
Using too small a diameter results in:
-
System overheating: Friction of oil against the walls of an overly narrow hose converts pressure energy into heat.
-
Cavitation: Especially dangerous in suction lines – too narrow a hose can destroy a hydraulic pump in a few minutes.
-
Loss of power: Instead of powering the cylinder, energy is "wasted" overcoming resistance in the hose.
Recommended flow velocities
For the system to operate efficiently and reliably, oil velocity should be within specific ranges, depending on the hose's function:
-
Suction lines (pump supply): 0.5 – 1.2 m/s (most critical section!)
-
Return lines (to tank): 2.0 – 4.5 m/s
-
Pressure lines (working): 3.0 – 7.5 m/s
Our calculator automatically uses safe, averaged values for each of these types to help you quickly select.
How to calculate it yourself? (Formula)
If you want to perform calculations manually, use the following formula for internal diameter:
d = √ [ (4000 * Q) / (60 * π * v) ]
Where:
-
d– internal hose diameter (mm)
-
Q– flow rate (L/min)
-
v– fluid velocity (m/s)
Complete your system with BRhydraulic
Once you know the required diameter, it's time to select the appropriate components. BRhydraulic offers everything you need for a professional hydraulic system:
-
Solenoid Valves: Ensure precise control of oil direction and flow in your system.
-
Hydraulic Cylinders: A wide selection of ready-to-use cylinders with various strokes and diameters, ready for work in the toughest conditions.
- CETOP Manifolds: Modular mounting plates and manifolds facilitating the construction of compact and efficient hydraulic systems.
Need help with a custom project? Our specialists can assist you in selecting not only hoses but also entire hydraulic control systems!
