1. Rubber Hose size measurement: inner diameter, outer diameter, reinforcing layer outer diameter, wall thickness, concentricity, inner and outer layer rubber thickness, inner diameter of the assembly. The new national standard and ISO increase the length and measuring point mark, and specify rubber hose without coupling and measuring method of rubber hose with coupling.
2. Hydraulic pressure test: Check whether the rubber hose and assembly are leaking, deformed and damaged for 30s-60s under test pressure. Pressure deformation test: hold for 1 minute under the specified pressure (working pressure, test pressure or other pressure lower than test pressure), measure the length and outer diameter change of the hose and torsion angle and bending. Burst pressure test: recorder the pressure at which the hose bursts at the specified boosting speed. Leakage test: maintainer a static pressure of 70% of the minimum burst pressure for 5 minutes, and repeat once to check for leaks or damage. Because the test often uses water, and the viscosity of the actual liquid is different, the burst pressure and leakage pressure measured at normal temperature may be slightly lower.
3. Low-temperature flexure test Low-temperature rigidity: rubber hose is clamped on a torsion wheel with a diameter of 12 times the inner diameter of the hose. After being placed at low temperature for 6 hours, the torque measured at 180° twisted within 12 seconds and the standard temperature are measured. Torque ratio. Low temperature bending: The hose is clamped on a twisting wheel with a diameter of 12 times the inner diameter of the hose. After placed at low temperature for 24 hours, it is twisted 180° within 10s to check whether the inner and outer rubber are brittle and damaged. The simplest test to measure the low temperature brittleness of the hose is to bend the sample at a low temperature by 90°, or to compress 1/2 of the hose after freezing to see if it is brittle, and another method is to freely drop it with a weight of a certain weight, impact test See if the sample is brittle.
4. Bending test: After bending the hose to a certain degree, measure the ratio of the minimum outer diameter of the bent part to the outer diameter before bending, the passing ability of the steel ball and the bending force when pressurized in rubber hose.
5. Suction test: Vacuum in 1min, hold for 10min, roll with a steel ball with a diameter of 0.9 times the inner diameter of the hose, and check the degree of collapse of the hose. Some standards use the change rate of the hose outer diameter to indicate the degree of hose deformation.