Hi I got a airtex 4500 w31 , looks alot like the one you want ,they look identical but aare not , I have had no problems and it tops off a big tank in like 5 minutes , and has replaceable filters , it came with 3 yr warranty I think they were like $3000 , I would say buy it and never worry about air , I also say go with the 220v
LOU
here is difference between airetex and alkin I found on web by owner of airtex
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AireTex 45 is NOT made in Turkey. It is designed and made in America. We do source parts from around the world but MOST of cost and all of the labor is America. I do purchase the 2nd and third stage heads from ALKIN in Turkey but that is all that comes from there.
AireTex 45 Compressor is very heavy duty, runs at a low RPM. AireTex 45 runs at 1050 RPM, all others run over 2100 RPM with the Coltri running 2800.
AireTex 45 is 220v-230v and draws about 23 Amps.
The AireTex 45 is the most durable portable compressor in my opinion and I have dealt with them all. In the 8 CFM range most all brands are good and in fact most share many similar parts. But on the small ones most are not durable and have many problems. I tried to eliminate those problems by design. Better internally balanced, lower RPM ,larger, longer and heavier rods. The crankshaft is supported on both ends with large bearings.
The ALKIN W31 we used to sell until 2006 was good in many ways but only supported by bearings on back fan side. We found that caused problems and failures. The larger ALKIN compressors are very good and we still sell those.
After looking at all of the competition and problems they had we designed our compressor from scratch. We do many things different than the others.
On a three stage compressor the first stage is large and builds pressure to say 100 PSI and into second stage that is much smaller. That compresses air further to about 450 PSI and into the third stage which the industry standard is 14 mm and that compresses it to 4500+ PSI. That is how most everyone else does it but it creates a few problems they have not addressed. Smaller piston is lighter so they are not internally balanced. Smaller piston does not have same room for rods, bearings and piston causing quick wear.
I addressed those issues by making the lighter piston steel machined to exact weight instead of traditional aluminum. Now my rotating assembly is internally balanced. By making the smaller piston steel I was also able to eliminate the wear that all of the others have such a problem with.
On the 3 rd stage floating piston I designed it similar to a valve on an airgun. Now it has well over twice the surface area and does not destroy the crosshead piston below it.
Those things make the AireTex 45 in my opinion the best portable made with the Bauer a good one to. There is not another compressor made under 4 CFM that I would recommend at any price. There are other design things we have done to make ours better but I do not think I need to be telling all of my secrets. Now they used to make a very nice military compressor but those are no longer available, they are hard to repair and parts are not available.
My years of building aircraft, working on airguns and building racing car motors have gave me a different look at how to design and build compressors.
Now I will say this the AireTex 45 weighs over 175 and some are around 120 and one is under 100 Lbs but they will not last as long. Now the AireTex 45 is also larger size so in addition to the weight it requires two people to pick up it is the best portable made in my opinion.
Hope I answered all of your questions and if you have any more just ask.
Bruce Dodson
AireTex Compressors
(214)402-5574 Mobile
(817)633-5505 Office
http://www.airetex.com 
