The cooking appliance (1) having a control panel (2) is equipped with one or more gas flow (Q) regulating valves, wherein the rotary regulating plug (6) is provided with various peripheral through holes (16-19). The control knob (9) being interchangeable for fitting to the actuating shaft (7), is chosen from the two units available, one and the other permitting different angular limit positions of the regulating plug (6) for the supply of a constant minimum gas flow Qmin, adjusted each one for a different type of gas N gas or LP gas. The outlet conduit (5) of the valve is equipped with a further injector nozzle (21,23) for adjusting a constant gas flow Qmax to be fed into the conduit (25) of the correspondent burner, when the cooking appliance is supplied with a LP gas.