If you were to sink a container to the bottom of a deep ocean and seal it there, then bring it up to the surface, would it retain its pressure?
The answer for a gas is obviously yes, but what about for a liquid like water which is incompressible? Once the crushing weight of the water column above is removed, does the water retain it's quality of "pressurizedness" or return to normal water? I guess a clear way to test this would be to bottle up a deep water fish and bring it up to the surface and see if it explodes.
While we're at it, what about a solid? Barring any elasticity and incidental temperature change, will a solid object break a non-sealed glass container which is exactly fitted to it and then placed in vacuum?
Best Answer
Water is slightly compressible, so it will hold its pressure as long as the container does not stretch.
But since it's only slightly compressible, if the container bursts under pressure it will probably not be an explosive failure. This is because at the time of failure, unlike a gas, the water does not push for a long enough time on the failing part of the container to generate much speed. This is why pressure containers are often pressure tested with water or oil instead of air or other gasses.
If a solid is slightly compressible, it will retain pressure inside a container. In practice, if a incompressible solid is enclosed in a pressurized container, there will usually be some gas or liquid mixed in with it that will retain the pressure.