Galactic radius vs the maximum restoring pressure by self-gravity of a gas disc. The solid black curve is for a thin gas disc with mass equal to that of AGC 226178, the solid dark blue curve for a thin gas disc mass twice that of AGC 226178, and the solid light blue curve for a thick gas disc of twice the mass of AGC 226178. The horizontal lines indicate ram pressure (RP) levels at three different cluster-centric distances from Virgo. The H I gas is stripped if the ram pressure is larger than the maximum restoring pressure. See Section 4.2.2 for details.