A hose assembly is usually composed of three parts: a hose, couplings (two pieces), and clamps or sleeves (if necessary). Couplings and sleeves usually have structures such as barbs on the parts in contact with the hose to achieve good friction between the couplings and the hose, ensuring that the couplings can withstand sufficient end forces during use.
The connection forms of metal couplings are divided into threaded and flanged. The common sealing types of threaded couplings include 24° conical surface O-ring elastic sealing, 74° conical surface metal hard sealing, and flat surface O-ring elastic sealing.
A few definitions:
- Length of hose assembly
The length of the hose assembly is the horizontal distance measured based on the end faces of the two hose couplings or the center of the elbow couplings.
The length of the hose assembly allows a manufacturing error of ±1%. If the hose is too long, it will affect the appearance and increase the cost. If it is too short, when the hose is compressed and extended or compressed, there is not enough room for expansion and contraction, which will also lead to the destruction of the hose.
- Angle of hose assembly
There is a concept of assembly angle only when there is a hose assembly with bent connectors at both ends. At this time, the definition method of the assembly angle is as follows:
Place the hose assembly on the same straight line, take the vertical direction of one bent connector at the far end as the reference, and measure the included angle between the other connector and the far end connector (vertical direction) in the clockwise direction. This included angle is the assembly angle. The allowable error of the assembly angle is ±3°.
- Hydraulic Hose Assembly Model Numbers
The model representation method of hydraulic hose usually adopts a code composed of numbers and letters to represent, including the following several parameters:
Inner diameter: The diameter of the inner layer of the hose, and the unit is generally in mm. The larger the inner diameter, the stronger the pressure-bearing capacity of the hose.
Wire diameter: Refers to the diameter of the steel wire or fiber used in the reinforcing layer, in mm. The larger the wire diameter, the stronger the pressure-bearing capacity of the hose.
Length: The entire length of the hose, in mm.
Pressure: The maximum pressure that the hose can withstand, usually expressed in bar. The larger the pressure, the stronger the pressure-bearing capacity of the hose.
In practical applications, the model representation method of the hydraulic hose may also include other special parameters, such as temperature range, bending radius, etc. Different combinations of these parameters can meet different usage requirements. When marking the hose assembly, it generally includes the following previous information:
The type of hose, including basic information such as hose structure and inner diameter;
The type of the left-end connector, including the structural form and thread specification of the connector;
The type of the right-end connector, including the structural form and thread specification of the connector;
Length, which is the definition of the straight-line length of the hose, in mm;
Supplementary information, such as assembly angle, sheath, etc.;
Other information, such as special properties such as high temperature resistance and corrosion resistance, represented by letters or numbers.
For example, the model of Parker's hydraulic hose:
F381CFCF282812-1800-270°,
where: F - indicates that the hose is crimped;
381 - series number, representing the series type of the hose, and its pressure range is 88-400 bar, general-purpose 2-layer steel wire braiding, and the temperature range is -40 °C to + 100 °C;
CFCF - the external connection form of the connectors at the left and right ends; 282812 - the outer diameter of the steel pipe at the external connection end of the left and right CF connectors is 28 mm, and the internal connection specification of the hose is 12 mm;
1800 - the total length of the hose assembly; 270° - the assembly included angle between the two ends of the hose is 270 degrees.
