  Gas accretion and radial flows are key ingredients of the chemical evolution
of spiral galaxies. They are also tightly linked to each other (accretion
drives radial flows, due to angular momentum conservation) and should therefore
be modelled simultaneously. We summarise an algorithm that can be used to
consistently compute accretion profiles, radial flows and abundance gradients
under quite general conditions and we describe illustrative applications to the
Milky Way. We find that gas-phase abundance gradients strongly depend on the
angular momentum of the accreting material and, in the outer regions, they are
significantly affected by the choice of boundary conditions.
