It has been generally accepted that any reaction between micropipes in silicon carbide (SiC) crystals requires a direct contact of the micropipes. We propose a new model of contact-free reactions that are realized through the emission and absorption of full-core dislocations by micropipes. This model can explain the correlated reduction in micropipe radii in the samples with low micropipe densities which has been observed in synchrotron radiation (SR) phase contrast images supported by computer simulations. We provide a theoretical description of a contact-free reaction between two parallel micropipes.