I have the original test documents from BioMarine way back when they were working with the spheres. As I recall, the lowest they ever got one of these things to fail was around 9500 psi, and the highest was somewhere around 14,000 psi. They never failed on the Weld either, usually on the upper hemisphere, perpendicular to the weld. Ian, you probably know when the CDBA 5000 psi ones were developed - was that by Carleton or the RN?