Abstract: NOx production from pressure-atomised burners is reducible by shaping, e.g. splitting, the fuel film leaving the burner. This is achieved, in accordance with the invention, by having an external wall 54 which surrounds the fuel outlet orifice 52 and from which external formations 56 extend radially inwardly towards the axis 20 of the burner. The formations 56 penetrate the frusto-conical pattern of fuel (not shown) emitting from the orifice 52 to split the flame into four discrete lobes. Other arrangements are possible in which different numbers of lobes are formed; or assymetric patterns are produced; or shaped flame patterns having no discrete lobes are produced.