  An $S$-ring (a Schur ring) is said to be separable with respect to a class of
groups $\mathcal{K}$ if every its algebraic isomorphism to an $S$-ring over a
group from $\mathcal{K}$ is induced by a combinatorial isomorphism. We prove
that every Schur ring over an abelian group $G$ of order $4p$, where $p$ is a
prime, is separable with respect to the class of abelian groups. This implies
that the Weisfeiler-Leman dimension of the class of Cayley graphs over $G$ is
at most 2.
