Rubber oil seal qualified products should meet the following conditions:
1. Oil seal surface should be smooth, no defects and no deformation.
2. The code symbol on the end face of the oil seal matches the requirement.
3. The shape of the rubber seal with the skeleton is correct, the end face is circular, and it should fit with the glass surface closely without distortion when put on the glass plate.
4. The edge of oil seal without skeleton should be correct, smooth end face, make it deformed hand and the original shape can be restored after let go.
5. The edge shape and thickness of the entire circumference should be the same, the edge of the neck should be tight fit with the parts when trial assembly.
6. When you have the bulk purchase of rubber oil seal, you can take some samples to do oil immersion test firstly, measuring the rate of change of quality. For example, soaking in the #25 transformer oil with 70℃/24h, the rate of change of quality should be 3% -5%.
7. In regards to the rubber oil seal with spring, the spring should be no corrosion and no deformation, and it can be put in the spring groove more firmly. As an example of 50×72×300px, free fall from the height of 1M, if the spring is taken off no more than 1 time in 5 tests, then the spring fits with oil seal well.