my chinese compressor project
Hi
I bougth a chinese compressor last month on alibaba and I start to modding it. You will find it identical to the on from mrodair.
I have add a water-oil separator between LP cylinder and HP cylinder. I take the time to make a coil that come close to the motor fan. On the high pressure side , I add a big coal filter and a PMV . I have no trouble with the low pressure pumping oïl. I also run a iso 150 oïl like the chemlube 751.
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I don t really know if there really a sell point in florida. Everytime I talk to Bill, he was in China. My 2 packages came from china also. If someone in that area can confirm, there will be part available for the mrodair compressor local! If some of you want to order something o this website, First contact the seller because what in the picture is not always what you will get. Ex: there is 6.7l bottle whit a fill station. What you will get is the bottle whit no fill station and I don t know if you will get the valve.
For what I understand , a PMV look to be unknown in china if @sincere have this on is compressor , I will be surprise. But if yes , I may buy one from him!
http://1007861.kancart.com.
(www.cng-scuba.com)
Interesting. Are these USA or Chinese compressors? Nice to have a USA service center for support though.
Thanks. Now I understand how you got the fittings to work. Swage locks.
That is unfortunate about getting an NR valve. Hopefully, you will have the right one soon.
Yes the tubing 6mm and it is more thick than thelow pressure side around 0.045- 0.050( no welding) it was suply with the parts I bougth from them.
Small update , my PMV is not a PMV , it is a NRV non return valve . The suplyer did not understand my request so he send me this. It will maintain the pressure in the tank instead to go back to the compressor. Now I have to source another PMV I found 2 different place , but the shipping is crazy to Canada.
All the fitting are swage lock type ss. We use swage-lock fitting where I work, and really love it!
Is the tubing you used to connect the water separator, filter and PMV (after the 2nd stage) a different type of tubing?
Also, how did you swage on the tubing? The Mrodair tubes appeared to have a conical fitting permanently attached to the pipes. Was it different on your compressor or were those actually bushings that can detach? I never tried to take them off the tubes on the Airmax.
I have no worry about the wall thickness as it is put on the low pressure side where it will see maybe 300psi. A 5/16SS 0.035 Tube is good for a 4000psi but when it is single welded tube, you multiply by 0.80= 3200psi so I should have a 10x factor protection, way more than what a good engeneer will take as factor protection. The compressor don t have the power to push 3000psi with is low pressure side, the piston is too big.
One of my next mod will be air filter and gauge for the low pressure side
Also , I did not pay 799usd for it!!!
The air filter came with the compressor, but I belive you can buy one with shipping for 100usd You can ask Bill for one. Look at the picture where you see all the spec on the plate , there is the website. He can sell you different model! He also have this website. http://www.cng-scuba.com but be carefull because there is no description, you must contact the seller before you buy anything by looking at the picture.
Ray, thanks for the advice regarding tubing wall thickness.
What is that old rule of thumb? Engineer for at least 5 times expected loads when failure can cause severe injury.
Link for the filter tower, where did you bought it an how much?
That is an unfortunate compressor. I have sold a lot of parts to owners trying to upgrade their $799 bargain. Electrically, they are dangerous. The wiring is WAY too light weight. We use #8 for the 110 motor since it draws so much amperage at pressure. And, their tubing is also too thin. That .035 that was mentioned may be OK on paper but we would never use use because of past problems with bursting. My minimum for a 4500 psi system is .049 annealed copper nickle or stainless.
Have fun working on it but PLEASE … BE CAREFUL!!
Anybody that gets hurt from a compressor failure negatively affects the entire high pressure compressor industry. And I sure don’t need that!
Some of the probleme have allready been fix ! Time will tell. What are the mod that you bring to your compressor that fix the probleme?
It’s a pity that you have been fooled.
The design of the air compressor is not reasonable.
Life is only a few hours
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Maybe I am missing something, but I think your tall, add on filter might be only activated carbon. You probably should arrange for a desiccant before air reaches the activated carbon. Otherwise, you’re delivering air with 100% humidity to the activated carbon instead of dry air. Remember, a water separator can only take the air down to 100% RH at the temperature and pressure of the water separator. That high RH% air will interfere with the activated carbon’s ability to adsorb hydrocarbons. Even worse, the water vapor will displace previously adsorbed hydrocarbons and cause them to be released.
Only with a desiccant BEFORE the activated carbon are you going to drive the RH% down to where activated carbon can do its job.
From…http://thedecostop.com/forums/showthread.php?10085-Understanding-SCUBA-Compressors-and-Filtration