I was looking at my neighbors HLVP gun today, a H.F. sprayer, it actually works well. I did notice though that there is an air pressure adjustment at the inlet, so using a gauge before the inlet, unless the air adjustment is wide open, is useless. Just something to ponder on, he had some problems getting his adjusted until I pointed that out to him.
"When I was younger, I could remember anything, whether it had happened or not." - Mark Twain