Secondary reg question

[motobrewer]

So, I bought this secondary reg, it has a 0-100 psi gauge on it.

pretty useless for what I'm doing, so, i'm wondering, can I just swap it out with a 0-30 psi gauge and that'll be fine? or is there some crazy innards that I have to mess with?

 

[AnOldUR]

Some regulators have a pressure release valve that will blow out below the safe range of the gauge, but as long as you're careful not to put 100 psi on your 30 psi gauge, it'll be fine. I replaced mine.