Present paper is continuation of the previous works but for the boundary conditions. Then equilibrium conditions of forces are the special case of more common conditions of equilibrium of angular momentum. The modified equations of conservation are conservation laws of density, linear momentum, energy and new law is law for angular moment is suggested. The problem of boundary conditions for a rarefied gas flow was studied both analytically on the base of the Boltzmann equation and numerically by the DSMC approach. It is well known. We discuss the problems that can be appearing to considerate the angular momentum variation in an elementary volume near the surface. The particles without structure were discussed.