Can I use a hydraulic pump for air?
I think they have a built in reservoir but I think I could pump into it at around 100 psi from a pre-compressor. Will this work or can it not pump air. Also, would it need oiled because it doesn't have the oil flowing through.
Just so you know I wouldn't be pressuring a vessel to 4500 psi by hand, I would rig up a motor for this.