Did I make a big mistake? I bought a Yong Heng compressor from China!!

Hello, everyone! New member here. I bought the Yong Heng compressor about six weeks ago. Just wanted to share a couple of things. I have only used it twice, because I fill a 60-minute tank. That tank lasts a long time. Each time, I have filled from around 2900 psi back up to 4400 or so. It appears that restricting the air flow can bog down the compressor enough to shut it down. My solution is to ensure the valve on the SCBA tank is open a couple of turns, as well as use a check valve male fitting on the tank side of the connection. My Stikman PCP fill station came with a check valve for doing two-stage fills. I simply connect to that. Then, I open the tank valve. Next, start the compressor with both bleed valves open. Close the low-pressure bleed valve first, then the high-pressure bleed valve. The pressure gauge on the compressor quickly builds up to tank pressure, then the air flow begins. Fill time from 2900 to 4400 is about 25-30 minutes. Dropping ice in the water bucket keeps water (and head) temps down. I thought I blew a burst disc on the second fill, but after changing it and looking at the old one, I think the fitting had just vibrated loose. Vibration is horrendous on this thing. My days as a helicopter mechanic (wayyyy back) tell me that it will be necessary to check the tightness of all the fittings on a regular basis. Small game season wraps up in a week or so, and I have had a blast this year hunting with my PCPs.
 
Any of you guys with the Yong Heng doing a direct fill to your gun? I was going to go the Nitrogen Route but dont really have the storage space, so I think I may order a Yong Heng compressor. I do most of my shooting at home so I was thinking this would work. I do not own a tank but my gun has a 250 bar carbon tank.(FX Crown) Do you think it would work ok? Would I need a different fitting than what comes with the compressor?
 
Wasn't sure if I should continue this thread or not, but the parts finally came into hook up a calibrated digital pressure transducer to the output port of the YH. I've been wanting to check the accuracy of the pressure gauge on it for awhile now - and I finally did this morning.

Basically, there's a stainless steel tee where the output pressure gauge once sat and tee'd into it is the original pressure gauge and the pressure transducer (horizontally mounted in the pic attached).

I don't have a graph of the data at the moment, but essentially the gauge on the YH is accurate. It tracked 1:1 with the transducer all the way from atmosphere up to 4800 psi when I cut it off. I would feel confident in saying the gauge reads to within +/-50 psi of the actual pressure - and actually my eyes are no better than that.

I'm still waiting/looking for the right adapter to attach this transducer to the output of the first stage. That's a bit involved because I have to standoff both ends of the steel tube by the same amount or figure out how to make a new steel tube. So one end needs a tee or combination of fittings for the transducer (M10x1.0 male on one end, 1/8" fpt on the tee and M12x1.25 male on the other end) and the other needs a coupler of the same stand-off length (M12x1.25-to-M12x1.25 male coupler). I may just have to machine my own tee from stainless because weird adapters like that just aren't available as far as I can tell, and the distances won't match up otherwise.

Nevertheless, it's good news that the gauge is reliable and accurate.

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Thanks... I was wondering what you were up to. Have you decided to tackle the first stage output cooling at all, or the cyclone separator between first and second stages with cooling fins? I haven't done much more to my two cylinder Tuxing, still working well, and I have about 3.5 hours run time on it. Oil still looks "purple", and still fills at about the same rate. It was interesting how fast first stage temperature goes up when the compressor is not loaded. Until I discovered that thanks to you, I was running the machine for about 2 or 3 minutes for a warm up, and then after the machine was done and depressurized, running it for 2 or 3 minutes to flush out any residual moisture. I've cut that down to no more than a minute on both sides...
 
First I want to thank all the contributors to this thread, a huge help! 

I received my compressor today, shipping was just about a week from an ebay vendor shipping out of CA. I made an offer of $250 delivered and it was accepted. The ebay vendor is yufann8_6.

It arrived today safe and sound and was packaged really well. 




The picture on the ebay ad showed no brand marketing and I was surprised that it had Yong Heng on it when it arrived. 


I was going to use Kobolt synthetic compressor oil. Thoughts? 


Last question, did you guys and gals use plumber's tape on the brass valve screws? 


Eric


 
Got my Yong Heng compressor last weekend . Offered $240.00 for 220v with adjustable pressure shut off. Figured I would run it on existing 220v line I already have @ home. When I opened the package there is only a standart 110v (type A) 2 prong plug. Unit clearly labled 220v inside case & on outside. Did some looking online and discovered europe and China have 220v residential source on a single wire. Already stepped up to 220v. Has anyone else purchased this type of compressor, and what did you do? Is anyone willing to post a few pics of the wiring & labels inside their 110v.unit so I could compare? Don't want to burn electronics or motor by just plugging it in. Thanks in advance.
 
Hawkeye51, I got the same compressor and cut the plug went to home depot got a 220 male plug and wired it on the end of the compressor, I also made a 10ft extension cord out of a old heavy #10 stranded electric cord. Been using it for a few months now and works great. I also bought a tile saw water pump to replace the one that came with it as it worked intermittently.(home depot royobe). I put a 7lb bag of ice and enough water to cover the pump and it keeps it cool for 34-40 minutes to top off my cf tank 106cf.
 
The piston rod on my Yong Heng seized. There is a dipper on the rod that mysteriously broke, thus depriving the crankpin of oil. I ordered a new piston assembly from Ali Express for only $20 BUT...... The new assembly second stage piston did not fit in the Yong Heng. The new part had 4 plastic rings, and the original had three. They looked identical in diameter, but in fact the new second stage piston was a few thousands too large. "Okaaaaaay....." sez me. "We're not done yet." I took apart the new assembly and moved the new rod to my old original piston set to replace the original rod that seized. This time the reassembly went smoothly. But after about a 3 minute run under no load to wear in the new rod I got a catastrophic failure. The failure point was where the first stage and second stage pistons are connected. I tried hard, but I'm done with Yong Heng. Even if yours runs great for a while, it will need a rebuild. I could not find a reliable source of correct parts. Without that, you're screwed at some point down the road. 
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