Reinforced flexible hose

A reinforced flexible hose includes at least one inner tubular layer (2) of plastic or rubber, a knitted reinforcement (3), which has substantially, parallel rows (4) and lines (5) of substantially parallel stitches, with respective stitch counts per unit length of the hose (Nm, Nr) ; and an outer layer (6) which is superimposed on the reinforcement layer (3) to protect it. The knitted reinforcement layer (3) is provided in the form of a single tubular layer and is wrapped around the outer surface of the inner tubular layer (2) ;the rows (4) and lines (5) of stitches are substantially helical, with respective longitudinal pitches (Pm, Pr) and inclinations which are mutually opposite with respect to the longitudinal axis (Y). The longitudinal pitch 2 (Pr) of the lines (5) of stitches is substantially proportional to the square of the outside diameter (&phgr;o) of the inner layer (2), whilst the number of lines (Nr) of stitches per unit length of the hose is directly proportional to the outside diameter (&phgr;o) of the inner layer (2) .