Even worse with those nails with the strips on them. I didn't myself , but a diabetic coworker I worked with did years ago. Had to take him to the doctor!
It has a bladder in it surrounded by air, I can't remember what the psi is set at, but there is a valve on the end of the tank. Use a tire gauge and check the air pressure. If the bladder is busted it will be the same as your water pressure.
Expansion tank is too handle minor fluctuations in pressure due to water being heated. Your water pressure needs to be at no more than 80 psi, (I don't recommend that much)anything over that does damage to your faucets and appliances. If your on city water check your pressure, adjust your...
Seriously, I'm a big proponent of privacy, sad thing is it doesn't exist anymore, but if someone wants to protect theirs as best they can, I'm am all for it.
Forgive me for my ignorance but why is it such a big deal to some? I really don't care much either way, it's not important to me but if a guy has a gun I want and asks me to sign it I'm not flipping out.