1: The pressure of the metal hose is not enough to cause blasting. Because the pressure and temperature of the conveying medium are too high, and the pressure resistance of the bellows is not enough, the explosion occurs. This kind of damage is caused by the error of design selection. It should be selected in strict accordance with the hose design selection standards, and the parameters of the metal hose and the parameters of the mesh sleeve should be determined.
2: Weld cracking. Most of the flexible corrugated pipe sections in metal hoses are longitudinal seam welded pipes. Often due to the quality defects of the longitudinal seam welding itself, the strength of the pipe is insufficient, resulting in cracking and damage at the weld. This damage belongs to the quality of the longitudinal weld of the bellows, so the control of the quality of the weld should be strengthened.
3: Wire mesh sleeve is pulled off due to virtual welding. The quality of welding are caused by the virtual welding of part of the steel wire (overburned or unwelded) during the three-in-one (the bellows, the ring and the wire mesh sleeve) welding process.
4: The wire mesh is broken. During the installation process of the metal hose, due to improper installation, or when the pressure is too high, the metal hose will be stretched and twisted. The mesh sleeve of the trinity welding part of the hose or the mesh sleeve of other parts is broken, and then the outer of the metal bellows is stretched and damaged, causing medium leakage. Therefore, the design and selection should be accurate and the installation should be correct.
5: Fatigue damage. In the dynamic working state, the metal hose is often subjected to fatigue crack damage under the action of cyclic load. Such damage is a normal failure. In order to prolong the service life, it should be ensured that the design and selection of the metal hose are correct, the installation is accurate, and the additional stress such as twisting of the metal hose is not caused.
6: The welding quality of the metal hose joint (inner connection part) is defective, causing the leakage of the metal hose. When the metal hose body is welded with the hose joint, when the operation is improper, welding defects will occur, and these defects are difficult to find during the pressure test inspection. When the metal hose is connected to the medium pipeline, after long-term use, the defect will be cracked or broken due to fatigue and other reasons, which will eventually cause the medium leakage of the conveying pipeline.
