the auto exhaust valve is related to the following two conditions (internal pressure and opening force):
1.The internal pressure inside the coffee bag must be greater than the atmospheric pressure outside.
2. The internal pressure inside the coffee bag must be greater than the opening force of the exhaust valve.
That is to say, when the air pressure inside the coffee bag is greater than the opening force of the exhaust valve and the atmospheric pressure outside, the exhaust valve will automatically exhaust, the coffee bag will only activate the exhaust valve when it reaches the above conditions of inflation.
