.[.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..]. .Iadd.A valve adapted to regulate the flow of both a natural gas and a liquefied petroleum gas. According to one implementation the valve includes a valve body having a rotatable regulating organ positioned between a valve inlet and a valve outlet, the valve outlet having a first restriction and a second restriction successive to the first restriction, the first restriction including a first hole calibrated to provide a given maximum flow rate of the natural gas at a first pressure in the absence of the second restriction, the second restriction removeably attached to the valve outlet, the second restriction including a second hole calibrated to provide a given maximum flow rate of the liquefied petroleum gas at a second pressure..Iaddend.

In certain embodiments, a valve assembly can comprise a housing, a valve body and a nozzle. The housing can define a first inlet and a second inlet. The valve body can be positioned within the housing and configured to rotate between a first position for a first fuel type and a second position for a second fuel type different from the first. A control knob is operatively coupled to the valve body and to an air shutter such that rotation of the control knob controls the state of the valve body and the position of the air shutter.