1. The hose has one or more ruptures, with neat cracks.

The main reason for this phenomenon is that the system pressure is too high, which exceeds the pressure resistance of the hose. If the system pressure meets the requirements, the actual pressure resistance of the rubber hose used should be checked to see if it meets the design requirements. 

2. Torsion occurs at the rupture of the hose.

The reason for this phenomenon is that the hose is subjected to excessive torsion during installation or use. After the hose is twisted, the structure of the reinforcement layer changes, the point between the braided or spiral steel wires increases, which reduces the pressure resistance of the hose, and the hose is easy to rupture under high pressure. Therefore, in the process of using or storing the hose, the hose should not be subjected to torsion torque. And the axis of the two joints should be on the same plane when installing the hose, so as to avoid the torsion of the hose in use.

3. The steel wire at the rupture of the hose is curled and there is a significant necking phenomenon

The reason for this phenomenon is that the hose is subjected to excessive tensile deformation, causing the layers to separate and reducing its compressive strength. The hose will shrink or extend in the length direction under the action of high pressure, and the general expansion and contraction quantity is 2 % ~ 4 % of that under normal conditions. If the hose is selected too short during installation, it will be greatly stretched during operation, and in severe cases, faults such as rupture or loosening may occur. If the span of the hose is too large, the weight of the hose and the weight of the oil will also give the hose a large tensile force, and in severe cases, the above faults can also occur. Therefore, the appropriate solutions should be taken according to the specific situation. If it is pulled too tightly during installation, an extended new hose should be replaced.