Hydrostatic test vent area

[pegus]

Good day,

I have worked validating chambers in which they performed pneumatic test, in which a component is filled with air and pressurized. For this validation there are tools that calculate the required vent area in case a decompression occurs, I understand that this is due to the air is highly compressible and the energy stored during a pneumatic test is greater than a hydrostatic test.

But I wonder what happens when a hydrostatic test is being validated (component filled and pressurized with water). If I understand correctly as the water is nearly non-compressible there is not much energy stored, and as soon as a failure occurs on the tested component, the water quickly decompresses and we dont have any air expanding and hitting the chamber. Do to this I have the following doubts:
1.-Do we need to consider any vent area for hydrostatic test?
2.-Do we need to take in consideration any possible projectile derived from the hydrostatic test? we do this for pneumatic, but I wonder if we need to follow the same path for hydrostatic test.

I would appreciate if you can recommend any reference to research more about it.

Thanks in advance,

 

[JStephen]

The answer is "it depends".
For high-pressure hydrotests on piping, pressure vessels, and similar items, a sudden failure can create some excitement. There's not a lot of energy stored in the water necessarily, but can be a fair bit stored in steel that is stretched to the elastic limit. I think I have seen some youtube videos on that; try looking for "hydrotest failure" or something like that.
I would agree with your thinking on the venting. Although there, a vessel "filled" with water could still contain some air pockets.
I see you are "Aerospace", so it might be helpful to know what you're testing.
Also, this is the "structural" subforum which mainly means buildings, bridges, etc., but not "aircraft structures".
For hydrotest on piping or vessels, try the "Boiler and Pressure Vessel" subforum. For aircraft-related questions, I think there is one or more aerospace subforums.

 

[dold]

I can't really speak to this with any authority, but I know that sudden failures in hydraulic systems can indeed kill you. Look up 'hydraulic injection'. Imagine someone trying to cover a leak with their hand. If it is just a static test without a pump running or anything, the risk would be smaller, but say in an active system this is a real danger.