A 1D bubble expansion problem is solved using standard compressible methods whose numerical solutions are compared with the exact low-Mach solution of the problem. The low Mach solution is proved to provide a very good approximation of the grid-converged compressible solution for a weak expansion and an envelope solution for the strong expansion. This motivates the design of a newly proposed Artificial Compressibility solver which will speed up low-Mach simulations of interest for nuclear safety with respect to standard compressible solvers.