MNJFLA - So far, all of my OEM stuff is working fine.
I just looked it up and found this -
"We place two cylinders into your penis along with a fluid-filled container in the abdomen and an inflatable pump in the scrotum, all connected through special tubing. When you squeeze the pump, fluid travels from this container to the cylinders, eliciting an erection. Releasing the valve makes the penis flaccid."
So you cannot "over-inflate" because it is fluid and not air like I was thinking, and there is only so much fluid in the container. I'm guessing that when the valve is closed, it makes it a one-way valve to pump the fluid in, then when opened, it allows it to return to the container.
Hopefully I'll not need one of these things any time soon, or ever, but it's always nice to know there are options if it came to that.