Igama elithi "3/4 ityhubhu ye-intshi" ngokuqhelekileyo ibhekisela kwi-diameter yangaphandle (OD) yombhobho. Ukumisela i-diameter yangaphakathi (ID), udinga ulwazi olongezelelweyo olufana nobukhulu bodonga. Ububanzi bangaphakathi bungabalwa ngokukhupha kabini ubukhulu bodonga ukusuka kububanzi bangaphandle. Akunakwenzeka ukumisela i-diameter echanekileyo ngaphakathi kwe-3/4 ye-intshi ye-tubing ngaphandle kokwazi ubukhulu bodonga.