It's fairly low, 4 psi I believe, somewhere around there... when I had a Electric fuel pump on my truck (didn't have the TIME and "engineering" to replace the defective mechanical unit- a royal pain to remove, I've done it twice!!)
I used a Solid state pump, self priming and they "tick" all the time. I had NO idling problems what-so-ever. It was designed for carbed motors.(no reg required)