We study the nonequilibrium steady state of disordered harmonic lattices whose Hamiltonian dynamics is supplemented by a stochastic flipping of the momentum of every particle. This dynamics conserves energy but not momentum. The one-body and pair correlations in this system are shown to be the same as those obtained for a model with self-consistent reservoirs, after an appropriate mapping of parameters. Results are presented, from numerics and simulations of a 1D system, on the dependence of the heat flux on the system size and on the flipping rate.