How do I not blow up my city water connection check valve?

Most people don't drain it and never have a problem caused by freezing.

rvhippo wrote:
What I don't understand is that one can send 40-50 psi of water or air through the valve during normal operation or winteriztion, but if I want to just release some trapped water, the valve can break so easily.

The check valve doesn't "break" ... rather excessive pressure causes the small rubber O ring inside to dislodge and the check valve can no longer seal properly. Simple solution - before pressing the check valve stem always relieve pressure in the system a bit by turning on one of your faucets for a few seconds, then close it again. There'll be sufficient pressure left in the system to push any unwanted water out of that city water inlet hose yet not enough to dislodge the O ring.

What I don't understand is that one can send 40-50 psi of water or air through the valve during normal operation or winteriztion, but if I want to just release some trapped water, the valve can break so easily.

Press the check valve in gently, and only far enough to let the water drain out. Mash on it, and there's a risk of unseating the o-ring seal. That's usually fixable, but it can be a pain to do.