150/180-2014 psi question.

I have a question regarding psi on my 150/180-2014 as well. I just installed a Dipricol electronic fuel pressure gauge and when I start the truck, my pressure goes to 40-41 psi and holds there. Even when I go WOT, it does not budge which I'm hoping this is a good thing and that's what it's supposed to do. When I shut the truck off, the gauge stays at 40-41 psi does anyone know if this is normal or is there an issue with the gauge. So is the 40-41 psi that I'm seeing on the gauge right? The transducer is in the gauge port on the FASS. Thanks