Which brand of dental dentistry compressor air pump to buy? Urgent request!

I do dental equipment maintenance work, first of all, do not recommend that you use medical oil-free air pumps, because the noise of medical oil-free air pumps at the beginning of the time is acceptable, a year later will be more and more big, and often out of a number of small problems, especially the Suzhou Junwei, I have two customers here with the Junwei, one of them burned the head of the pump twice, the other often appear unknown noise, but also to find out the reason, the warranty period has changed a few pump head has little effect, and then out of the warranty period the manufacturer will no longer give the replacement of only paid maintenance. Reason, the warranty period has changed a few times the pump head is not much effect, and then later out of the warranty period manufacturers will no longer give the exchange, only to paid maintenance. Other brands are not very clear. If the environmental conditions allow you to recommend the use of industrial pumps, a cheap, and then is stable performance, and then add a few more oil-water separator and the overconsideration, the same can work. If conditions do not allow, we recommend that you use the Foshan end of the tooth, the price of a tow of one thousand five, a tow of two is one thousand eighty, and with the Guangshun pump head, accessories are basically universal, maintenance is very convenient!