Steel Wire Spiral Hose Inspection Process Analysis

Steel wire spiral hoses, as important flexible connecting components in the industrial field, are widely used in hydraulic transmission, gas transportation, and high-pressure fluid media transmission. Their performance directly affects the safety and reliability of equipment operation; therefore, a rigorous inspection process is a key step in ensuring product quality.

Appearance and Dimensional Inspection
The inspection process begins with appearance and basic dimensions. Visual inspection is performed to check the hose surface for defects such as bubbles, cracks, impurities, or exposed steel wires, ensuring that the inner and outer rubber layers of the hose are free from obvious mechanical damage or manufacturing defects. Subsequently, calipers or specialized measuring tools are used to measure the hose's inner diameter, outer diameter, and wall thickness to verify compliance with design standards. Dimensional deviations must be controlled within industry allowable limits (typically ±0.5mm).

Pressure Resistance and Burst Test
Pressure resistance is one of the core indicators of steel wire spiral hoses. During testing, both ends of the hose are sealed and connected to a high-pressure testing device. Test medium (such as water or oil) is injected at a constant rate, gradually increasing the pressure to 1.5 times the nominal working pressure (e.g., if the working pressure is 20 MPa, the test pressure is 30 MPa). The pressure is maintained for 5-10 minutes, observing for leaks, bulges, or joint detachment. For the burst test, the pressure is further increased to the hose's limit (usually 3-4 times the working pressure), and the maximum pressure value at rupture is recorded to ensure the actual burst strength is higher than the nominal value.

Bending and Pulse Fatigue Tests: To simulate dynamic loads under actual working conditions, the hose undergoes a bending test. One end of the hose is fixed, and the other end is repeatedly bent at a specified radius (e.g., 5-10 times the hose's outer diameter) more than 10,000 times, checking for wire breakage or rubber layer delamination at the bending points. The pulse fatigue test uses high-frequency pressure cycling (e.g., 6-10 times per minute, with pressure fluctuating between 0 and the working pressure) for more than 500,000 cycles to evaluate the hose's durability under long-term alternating stress.

Adhesion and Steel Wire Winding Testing: The bonding strength between the inner rubber layer and the steel wire reinforcement layer of the hose directly affects its peel resistance. Shear tests or peel tests are used to measure the bond strength between the rubber and the steel wire, requiring a peel strength no less than the industry standard (typically 5-10 N/mm). Furthermore, X-ray or ultrasonic testing is necessary to check the uniformity of the steel wire winding, ensuring that the number of layers, pitch, and tension meet design requirements and preventing localized stress concentration that could lead to premature failure.

Through this systematic testing process, the overall performance of the steel wire wound hose can be comprehensively verified, providing reliable quality assurance for industrial applications.