With more than 17 years' experience of oil seals selling and researching, I found many people have misunderstanding when choosing and buying oil seals, now I share it to you for reference and welcome to correct my view if you think it is unreasonable, Thanks.
1.The more expensive , the better.
First there are several factors have to be considered when we select oil seals, we have to judge whether it is suitable for us according to the working environment such as :sealing medium,working pressure,working linear speed,working temperature etc, so it not means that material is more expensive then we can get the best effect.As we all know, the viton material is expensive, because it can bear the working temperature from minus 20 degree centigrade to 230 degree centigrade and have large range of temperature resistance , medium resistance and low friction coefficient,but the low temperature resistance( the minimum temperature is minus 40 degree centigrade) is not good compare with NBR material.If your equipment works in low temperature long time and also both of the linear speed and working temperature are not high, I think NBR is a good choice.
General speaking,if it is suitable for the working environment of your equipment then it will be the best choice.
2. Advocating foreign brands.
If domestic oil seals worked not so well then prefer to import.
Oil seal leakage is a comprehensive performance, oil seals on the outer side and they are the last line of defense, but the feeling bring to us is that the oil seals have problem. Actually, about the oil leakage,we should rule out the following points then to judge whether it is the problem of oil seals:bearing bouncing, surface smoothness of shaft and whether the installation method is correct, after eliminate these issues, then you can focus on the problem of oil seals.( We also have to know that many not good manufacturers sell the shoddy even counterfeit then affect homebred brand reputation.)
3.People don't understand the working environment of equipment.
I once served a customer who need a kind oil seal( Please note that it is oil seals)and it resist to 400 degree centigrade .
At that time I asked him :" what is the sealing medium of the oil seals because consider the high ignition temperature and most of the lubricating oil burned at this temperature".
After many times communication, I got that the heat source is close to 400 degree centigrade but the axial temperature of the oil seal contact is only around 190 degree centigrade.
The customer said :" I chose the normal NBR material of TC oil seals before and they not worked soon, the RPM of the shaft is low (below 100r/min) " ,after know this, I advice him to buy the same size but with viton material, it has been confirmed later that viton material is more durable than normal NBR.
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