If R is an integral domain, let C be the class of torsion free completely decomposable R-modules of finite rank. Denote by R the class of those torsion-free R-modules A such that A is a homomorphic image of some C ∈ C, and let P be the class of R-modules K such that K is a pure submodule of some C ∈ C. Further, let QR and QP be the respective closures of R and P under quasi-isomorphism. In this article, it is shown that if R is a Prufer domain, then QR = QP, and R = P in the special case when R is h-local. Also, if R is an h-local Prufer domain and if C ∈ C has a linearly ordered typeset, it is established that all pure submodules and all torsion-free homomorphic images of C are themselves completely decomposable. Finally, as an application of these results, we prove that if R is an h-local Prufer domain, then R = QR = QP = P if and only if R is almost maximal.