Sir the “normal” size supply line to the “power assisted tank” is 3/8th of an inch.( not including the severe restriction the globe valve causes with a 1/4″ opening in many cases.)
Using a 2″ supply pipe (Riser) I could take off 28.5 3/8 pipes to get the same volume.
With a 3″ line I could supply 62+ toilets with a 3/8 supply to get the same volume.
Are you sure your not thinking of a flushometer, like the Sloan Royal 110 etc instead of the Sloan Flushmate (Pressure assisted tank bladder) Good Luck in your Quest