P 1*V 1=P2*V2
Or: P 1/P2=V2/V 1.
Because the change of V2/V 1 is very small, and the change of pressure in the tube is also very small, it is easy to pull out the syringe naturally.
Without a vacuum, the hemisphere of Fort Madre should be easily torn apart.
According to your modification, it can be understood that the syringe is placed horizontally and cannot be pulled out, because VI is about 0, P 1 yes 1 atmospheric pressure, and V2 is set as the volume of the syringe. If the syringe is pulled out, the vacuum degree is far less than -0. 1MPA, so it cannot be pulled out.