Working Bore Sizes Pressure 7-1/ 16" 9" 11" 13-5/ 8" 16-3/ 4" 18-3/ 4" 20-3/ 4" 21-1/ 4" ( PSI) ( 180mm) ( 230mm) ( 280mm) ( 346mm) ( 426mm) ( 476mm) ( 527mm) ( 540mm) 100 00 ( ( ( 5000 ( ( ( ( ( ( ( 3000 ( ( ( ( ( 2000 (