Hydraulic Hoses can be classified into 4 categories based on their working pressure.
1. No Ferrule Hoses
Useful in low pressure environment (bellow 20bars) There are installed with pressure equipment and there’s no need for ferrules as hose fittings
2. Low Pressure
They have one or two threads along with one wire
3. Medium Pressure
They have one or two wires and they are the return line hoses.
4. High Pressure
They have 4 or 6 wires
Working Pressure: The pressure in which the hose is designed to work. The most useful unit for it is Bars.
Burst Pressure: The least of pressure in which a hose bursts. That means if we test various parts of one hose in this pressure, the lowest degree of pressure is known as the burst pressure.
Nominal Diameter: The inner diameter of the whole which is used to determine the hose’s size. This size is usually measured in Inches.
Minimum Bend Ratio: The minimum of the ratio in which the hose can be bent.
The role of Hydraulic hoses is connecting parts that move relative to each other. Therefore, the "bending ratio” is one of the most important factors in selecting a hose. Since in the bending condition the inner tube and the hose surface are stretched and therefore thinner, the hose resistance to pressure drastically decreases.