Telescoping Tubing Extended with Air Pressure or Springs?

[Bill_B]

Originally Posted by vivek16

120 psi in AIR pressure. Most pvc is rated for liquid.

-vivek

And the difference to the structure (presuming it not to be soluble in the liquid) is what? That is, I know that liquids are sometimes used in the pressure testing of gas enclosures, but I do not know of any ratio or factor as a part of that testing. 120 psi is 120 psi regardless of the fluid. However, in the liquid's case the expansion of the fluid to reach zero psi is smaller. This makes a failure in the tested device somewhat less catastrophic and also mitigates the likely trajectories of fragments. Anyone involved in such testing to determine fracture points MUST take precautions that protect them from all possible failure modes.

[Chris is me]

Originally Posted by Bill_B

And the difference to the structure (presuming it not to be soluble in the liquid) is what? That is, I know that liquids are sometimes used in the pressure testing of gas enclosures, but I do not know of any ratio or factor as a part of that testing. 120 psi is 120 psi regardless of the fluid. However, in the liquid's case the expansion of the fluid to reach zero psi is smaller. This makes a failure in the tested device somewhat less catastrophic and also mitigates the likely trajectories of fragments. Anyone involved in such testing to determine fracture points MUST take precautions that protect them from all possible failure modes.

Liquid isn't compressible.

The best precaution to take against preventing failure of a PVC system is to not use it for air. It's the only one, actually.

Regardless of any safety concerns, PVC is not a pneumatic component.

[Bill_B]

Originally Posted by Chris is me

Liquid isn't compressible.

...

Chris, take a little time away from your studies and check http://hyperphysics.phy-astr.gsu.edu.../compress.html concerning the compressibility of liquids.

Have you heard the riddle: which would you rather have fall on you, a ton of bricks or a ton of feathers? I'm pretty sure either load would crush you.

The question remains then what is the difference between 120 psi air and 120 psi liquid as it pertains to the structural integrity of the container.

We are in agreement about pressurizing the PVC for use in the Breakaway game - not legal.