You're not good at understanding the written word are you?Point out which bit of what I wrote is wrong, then.
I'm not saying you were wrong that there are valves for inhaling and exhaling, I'm saying it's bloody obvious.
But since you're hard of thinking, Scuba tanks are typically around 200 bar. The pressure regulator reduces that pressure to the same as the surrounding water to avoid exploding your lungs. That also includes the inhale valve. The exhale valve is to stop water getting in but to allow used air out.