Yong Heng 1st stage inlet air pressure

I have a Yong Heng compressor. I also have a shop compressor outputting 90 psi. I am considering hooking my shop compressor outlet to the Yong Heng first stage inlet to supply drier air to the 1st stage of the yong heng. I will attach a drier and filter to my shop compressor outlet. This setup will allow my shop compressor to condense a lot of water out of the ambient air before it goes to the yong heng 1st stage.

Has anyone tried this setup?

Does anyone know the yong heng 1stage outlet pressure?

What is the thread pitch on the yong heng 1st stage inlet manifold?

Thanks!
 
I have done some experimenting with this and typically boost my inlet pressure using dry air at 5 psia. The 1st stage is a 10:1 compression, so I wouldn't feed it much more than 10psia as a boost. I tried up to 20 psia then got scared to go any higher. When the inlet pressure is 1 atmosphere as in typical usage, it outputs ~150psi. With a 10psi boost, it will be outputting ~250psi. Also, both the first stage cast iron and the second stage cylinder/piston will run hotter. I wrote up some detail on this here:

https://www.airgunnation.com/topic/pre-compression-desiccant/#post-289365


 
Please don't do this unless you regulate the output pressure from your shop compressor back down to atmospheric pressure. The Yong Heng was designed to start with atmospheric air pressure into the first stage. If you run any significant pressure into it, you could find your Yong Heng turning into a grenade. It's possible that it would hold together, but I wouldn't bet on it. If your YH is a 115 volt model, then it is already near the limit of how much power a wall outlet can supply, and feeding higher pressure air into it will increase the power demand a lot.

However, if you reduce the outlet pressure of the shop compressor back down to atmospheric, after running it through a filter/drier, then I don't see why it wouldn't do an excellent job of supplying you with lots of dry, clean air. Let us know how it works out for you!

James
 
Klripper, it's up to you, but I just use 5psi input to mine. If you go with 15psi (so 30 psi total), you'll have 300psi at the output of the first stage because the first stage compression is 10:1. Feel free to read through the thread I linked above where I did some experimentation on using the YH as a booster with a slight overpressure on input (up to 20 psia or 35 psi total at the inlet)). It definitely saves on pumping time, but everything runs hotter and you'll be at double the pressure on the first stage compared to standard one atmosphere input. Probable don't need to say this, but please be careful.

Also, the inlet threading on my YH is not 1/4 bspp, mine is M12-1.25. but maybe there are several versions. Not sure.
 
Thank you prfssrlee. Your post was exactly the thread I was searching for before posting this one. I have already ordered a replacement second stage piston and rings. I am very interested in your results with vfd and reduced motor speed. My intent was not to decrease fill times but just provide dryer air to the YH. I have subscribed to the thread you posted a link to above and look forward to learning of your results. 

I will also limit the first stage inlet pressure to 5 psi as that is the minimum setting of my regulator. 

I ordered the 1/4 bspp fitting on the advice from airgunfans but will go ahead and order a M12-1.25 as well.