Topological defects play a fundamental role in the analysis of symmetries and dualities in 2d CFTs. In this talk, I present a lattice regularization for topological defects in critical integrable lattice models based on the Temperley-Lieb algebra, which include the Ising model and the 3-state Potts model. While the lattice regularization for some defects (those of so-called ``s-type'') was already well known, the regularization for ``r-type'' defects has previously not been well understood. A crucial difference is that s-type defects are topological already on the lattice, while r-type defects are topological only in the continuum. Here, the regularizations of r-type defects are obtained from those of s-type defects by using defect flow. I show how the validity of the construction is verified numerically, including by determining the g-functions through computation of the entanglement entropy in the presence of the defects.