{TAIL ~ The method} and structure includes defining an inner circumferential seat, and {HEAD ~ an outer circumferential seat}, in the vessels bottom, those seats being disposed inside of and outside of, respectively, the circular wear path previously formed in the bottom 
{ TAIL ~ The method } and structure includes defining an inner circumferential seat , and { HEAD ~ an outer circumferential seat } , in the vessels bottom , those seats being disposed inside of and outside of , respectively , the circular wear path previously formed in the bottom
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH