Amorphous magnetoelastic alloys show outstanding magnetic and magnetoelastic properties that make them excellent candidates for simple detection and actuation devices. The coupling between elastic and magnetic properties reflects in the dependence of the Young’s modulus with the applied magnetic field. We present a study of the change of the Young’s modulus with the applied magnetic field in ribbons of Fe-Ni-Co-Si-B composition. Strips of different lengths (L = 35, 30, 25, 20 mm) and widths (w = 5, 3.3, 2.5, 1.7 mm) have been measured and obtained results analyzed in terms of the different length-to-width ratios (4 < R < 21). From our observations, depth of the ΔE effect reduces and needed applied magnetic bias field for minimum Young’s modulus value increases as the strips shortens. In order to test the applicability of these materials in a situation of open/close simple designed gas valve, FEM simulations have been performed by using the experimentally measured Young’s modulus values, searching to estimate the maximum deflection of such a strip when working under applied constant pressure. Obtained useful deflection ranges from 1 mm to 10 mm, telling us about the feasibility of this amorphous magnetoelastic ribbons for simple gas valve applications.