Friday, June 20, 2008

Floats as Tanks

This is a picture of hydrotesting I did on a 6" 316 Stainless steel float from McMaster-Carr (2762K49). It failed at 2150 psi. Interestingly, the failure was a tiny pinhole that opened right at the weld termination. My grease gun was not able to pump enough water fast enough to get the pressure higher higher than 2150 once the hole opened up.

I proof tested a second of these floats to 1900 psi without failure. And 3 more were tested to 1500 psi.


Lorenzo il Magnifico said...

You blitz my brain with your startling engineering perspicacity
God Bless you and all who sail near you

James said...

How much do you tanks weigh? I get about 1.6 lbs based on standard metal gauge thicknesses. Are your tanks close to that?

Rocket Dude said...

My triple beam balance reads 670 grams. They aren't going to win any records for mass ratio, but they can be useful.

And for the record, using them as tanks was not my idea. At least, XCOR has been using them for a long time and perhaps others even longer.

bill said...

Cool stuff! I had no idea a grease gun could be used for a hydro test. Fascinating!