Yesah,so if you buy a tristamed tank and rehydro it on just say only a pi cert then carries all 3 certs get carried over?.
but if you just buy a pi stamped tank(single cert) you cant add anymore certs to that tank its just a pi stamp until deth no matter what you do.
Strictly speaking the test isn't a DOT/TC/TPED(Pi) test, it's a test that the cylinder is still within tolerance
DOT/TC/Pi are original markings that it is manufactured and approved to the standards of by the Department of Transport(US), Transport Canada, and/or Transportable Pressure Equipment Directive (Europe).
Pre TPED we had British Standard numbers. Before BREXIT kicks in we have to decide whether the existing legislation and the TPED standard remains, or that we create new British standards
A new standard may be a bit inconvenient if it means new cylinder manufacture post BREXIT have to be approved for a British standard