The high pressure hose structure includes two parts of flexible bellows and joints, flexible bellows are covered with stainless steel wire mesh sleeves for protection and pressure, and the joints are divided into parts connected with the bellows (internal connection part) and the engineering pipeline (or body) connected part (external connection part). When selecting hoses, the appropriate hoses, fittings and hose assemblies should be selected according to the specific application.
The cracking and leakage of the bellows in the high-pressure hose are generally the following reasons:
(1) Weld cracking in the flexible corrugated pipe section of the high-pressure hose, most of the longitudinal seam welded pipe, often due to the quality defects of the longitudinal seam welding itself, the pipe strength is not enough to cause cracking damage at the weld, this damage belongs to the quality problem of the longitudinal weld of the bellows, so the quality control of the weld should be strengthened. When selecting high pressure hoses, the appropriate hoses, fittings and hose assemblies should be selected according to the specific application. The ultra-high pressure hose is a hose made of SPIR STAR made in Germany. The reinforced layer of the high-pressure hose is a specially treated high-strength steel wire winding layer, the inner adhesive layer is polyformaldehyde (POM) or polyamide (PA), and the outer adhesive layer is the corresponding polyamide (PA) or polyurethane (PUR).
(2) The bellows' pressure is not enough to burst because the pressure and temperature of the conveying medium are too high, and the bellows' pressure is not enough to burst. This kind of damage is caused by the design selection error, should be strictly in accordance with the high-pressure hose design selection standards for selection, to determine the parameters of the bellows and mesh parameters.
(3) Corrosion erosion perforation damage Because the material quality of the bellows is mostly Austenitic stainless steel, which contains more non-hydraulic inclusions (such as silicate, oxide, TiN, etc.), when the corrosive medium (decisive substance) in the pipeline, it will form corrosive penetration microholes on the edge of the weld fusion line or other weak points. Bellows pipe is very thin, generally in 0. It's 15-0. Between 8, the formation of corrosion penetration on such a thin material is very easy, to prevent such damage. It is necessary to choose qualified stainless steel strip (sensitization and other series of tests qualified), but also to prevent the damage of the bellows caused by external mechanical damage in production and transportation.
(4) Fatigue failure In the dynamic working state, the high-pressure hose is often subjected to cyclic load fatigue crack failure, such damage is a normal failure. In order to extend the service life, it should be ensured that the hose design and selection are correct, the installation is accurate, and the high-pressure hose does not produce additional stresses such as distortion.
