1, to see whether the product code on the end face of the oil seal is consistent with the required.

 

2, to see whether the surface of the product is smooth, no defect, no deformation.

 

3, for the rubber oil seal with skeleton to see whether its shape is correct, good oil seal end face should be circular, put on the glass plate should be fit with the glass surface, no disturbance phenomenon.

 

4. The outer edge of the non-skeleton oil seal should be straight first, and the end face should be flat. In addition, it can be deformed by holding it by hand, and then it can be restored to the original shape.

 

5. For the judgment of the cutting edge, the shape and thickness of the cutting edge on the entire circumference of the oil seal should be changed to be consistent. When fitting with the accessories, the cutting edge should be closely fitted on the matching neck.

 

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6. For the rubber oil seal with spring, first of all, the spring should have no rust, no deformation, and be tightly and firmly stuck in the spring groove. The test of this oil seal can also be verified by a simple small experiment. First, the oil seal is allowed to land freely from a height of 1m. If the spring falls off no more than 1 time for every 5 times, then it can be considered that the spring and oil seal cooperate well.

 

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7. When buying oil seals in large quantities, it is very important to randomly select a sample for oil immersion experiment, especially for some dealers. This measures the rate of change of the mass of the device. For example, for the oil seal with 25 transformer oil in the temperature of (70±5) degrees after soaking for 24h, the mass change rate should be between 3%-5%