Some updates for the thread
After some time of use I have found mistakes made, when planning the compressor scheme. For not to describe many things, I'd say it briefly. Fridge compressor MUST be in the upper point of the compressor system, as there's oil and condensed water in the pipes and it flows down.
In my compressor this water was going back to the compressor and it's wrong. So I've solved the issue by installing some parts into the system, which are seen on the photo. The drain valves are installed so trapped water and oil could be taken out.
So I think everything is goona be OK with this issue.
There was also an issue with the air receiver. It's rusted through where legs were welded.
So if I'd know it would happen, I'd never bought and moreover had spent time on this type of the tank. It has thin body, so air leak problems is just a matter of time.
The problem was solved by welding, but new air leak will appear in future, I think.
Next time I will never buy the receiver for home pump, at least it will be stainless steel.
And I'd recommend to use liquid thread sealer instead the teflon tape. You will not have air leaks from the start. BTW factory made compressor go with liquid sealing, so I think it speaks for itself.