Posted by Eins on January 29, 2001 at 21:46:44:
In Reply to: Some Facts, For A Change ??? posted by Kevin on January 29, 2001 at 15:32:13:
Kevin,
Thanks for your post, and it deserves a separate response.
Stress may or may not result from dynamic elastic expansion (DEE). If DEE is measured, stress is automatically measured too.
Again, there is NO difference in the testing PROCEDURE for a steel LP to get a + than for any other [scuba] tank. [There are only differences in the absolute test pressure.]
The procedure (leaving description of water jacket apparatus and measuring instruments out of this discussion) requires to measure tank expansion and shrinkage (in lack of a better word) at a test pressure 5/3 of the service pressure of the LP tank. This procedure remains unchanged, whether testing for + or not. Only the service pressure and therefore the hydro test pressure is variable. For a + rating, the service pressure is the allowed overfill pressure.
If you think otherwise, please explain. Or better, call the DOT and let them confirm what I said. And then post your insights here.
Eins