I. Visual inspection to hose appearance.

Hoses must be uniformin diameter.For hoses with glossy surface, users should make sure the hose surface is smooth and free from embossment, bubble, sponge, sand holes or surface scratches, and as for hoses with mat surface, the patterns must be uniform.

II. Checkinnerrubber layer elasticity by pinching.

Smooth and elastic internal surface indicates high rubber content, vice versa.

III. Check hose concentricity and uniformity of rubber distribution ininnerandouterlayers.

Inspection should be made to cross-section of hoses, to make sure that the internal hole and wire layer are round and in proper position and that theinnerandouterrubber layers are in uniform thickness. Higher brightness reflects better quality.

IV. Uniform wire reinforcement layer.

Steel wires should be in good order and continuous, without overlapping, and should be braided in appropriate density. Higher density indicates better quality.Apply certain forces by finger on the wire layer andinner/outerlayers, insufficient adhesive force between rubber layers and wire layer indicates unsatisfactory quality.

V. Two important indicators: Pressure capacity and impulse performance.

Impulse performance test is the most comprehensive test on rubber hoses, in which process the overall structural compactness of hoses are of greatest importance.Pressure test includes low pressure test and high pressure test, and should be done in closed environment with water as its medium.Test pressure in low pressure test is 1MPa, and will be kept for 5 minutes. The test hose is acceptable if no leakage is found.In high pressure test, the test hose is acceptable if no burst is found, in which process attentions should be paid to adjacent environment, and unauthorized access should be prohibited to avoid personal injury.

VI.If rubber hoses are required in large volume, user may soak the test hose in diesel for 24 hours in most cases.  This test aims to measure the expansion rate. Smaller expansion rate means rubber has been properly vulcanized with satisfactory performance in all aspects.