Comment by dotancohen
2 days ago
LPG explosions are real combustion due to tank rupture (often due to installation damage or rust). A nitrogen COPV can not rupture (that's why the CO in COPV is there) but it can leak. And that COPV, when it leaks, will be a rocket. But not an explosion.
10,000 PSI? That is beyond absurd. I can not imagine what alloy and how wrapped that pressure vessel is... Or what type of crazy pump is recharging it!
> A nitrogen COPV can not rupture (that's why the CO in COPV is there) but it can leak.
They'll happily burst (https://www.youtube.com/watch?v=YJ-__PlU4gM) and blow up your vehicle (https://www.youtube.com/watch?v=71AwkBt3_ts).
https://www.space.com/space-exploration/launches-spacecraft/...
"'Initial analysis indicates the potential failure of a pressurized tank known as a COPV, or composite overwrapped pressure vessel, containing gaseous nitrogen in Starship's nosecone area, but the full data review is ongoing,' the company wrote in an update on Thursday (June 19)."
> LPG explosions are real combustion due to tank rupture…
They're mostly designed to vent (https://en.wikipedia.org/wiki/Rupture_disc) to prevent a BLEVE. Big fire, big mess, but without oxidizer in the tank and much lower pressures, relatively safe by comparison. https://www.youtube.com/watch?v=JQDyNjCNxVY
That first video is terrific - but it demonstrates bringing the pressure vessel far beyond design limitations. Would you like to see what a tank of gasoline does when taken far outside design limitations?
The other two videos are triggered by the copv failing, but the explosion is due to the methane and lox.
My point still stands. The composite overwrap either survives a collision (crash tests will determine this) or doesn't (the vehicle will not be legal for sale in the US and Europe). The crash conditions are inside the design limitations, just like the batteries are and just like a standard fuel tank is.
> The other two videos are triggered by the copv failing, but the explosion is due to the methane and lox.
Sure. For the car, the COPV rupturing is gonna look more like https://en.wikipedia.org/wiki/Byford_Dolphin.
> the vehicle will not be legal for sale in the US and Europe
I think that's already safe to assume.