Is the constant pressure valve chamber good or small?

If the spring force is greater than the pressure difference, the piston will not continue to move to block the air intake, the air intake will continue, and the air pressure in the constant pressure chamber will continue to rise. With the increase of air pressure in the constant pressure chamber, the pressure difference between the two ends of the piston increases, which increases the resistance of the piston to the spring and will move forward. When the spring is compressed, some forces increase and there is an equilibrium position between them.