How Does Pressurizing a Sealed Syringe Affect Internal and External Pressures?

AI Thread Summary
Pressurizing a sealed syringe does not result in an equal pressure decrease outside, as the external pressure remains atmospheric. When the syringe is connected to a piping system with a non-compressible fluid, an increase in fluid pressure leads to a corresponding increase inside the syringe, but this does not equate to a pressure drop in the fluid system. The internal pressure of the syringe and the external pressures do not directly correlate in these scenarios. Understanding these principles is crucial for accurate pressure management in fluid systems. The discussion clarifies misconceptions about pressure dynamics in sealed environments.
fpdlskf
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Problem is simplied.

Assume ideal gas @ atm pressure & temperature.
Completely seal the needle end of a syringe.
Assume bottom end of syringe is completely sealed (can move in axial direction).

Q1.
If I press on the syringe (pressurize inside), is if correct to say that the pressure increase on the inside of the syringe is equal to the pressure decrease on the outside (open to atm)?

Q2.
If non-sealed side of syringe is connected to a piping system in which a non-compressible fluid is flowing, a pressure increase in the fluid will cause a pressure increase inside the syringe. In this case is it correct to say that the pressure increase on the inside of the syringe is equal to the pressure drop in the fluid (piping system)?
 
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fpdlskf said:
Problem is simplied.

Assume ideal gas @ atm pressure & temperature.
Completely seal the needle end of a syringe.
Assume bottom end of syringe is completely sealed (can move in axial direction).

Q1.
If I press on the syringe (pressurize inside), is if correct to say that the pressure increase on the inside of the syringe is equal to the pressure decrease on the outside (open to atm)?
No. The pressure outside stays atmospheric.
Q2.
If non-sealed side of syringe is connected to a piping system in which a non-compressible fluid is flowing, a pressure increase in the fluid will cause a pressure increase inside the syringe. In this case is it correct to say that the pressure increase on the inside of the syringe is equal to the pressure drop in the fluid (piping system)?
No.
 
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