TY JOUR TI ENSURING TIGHTNESS IN PRESSURE COUPLING PARTS KW pressure coupling tightness KW microgeometry KW material and coating of mating surfaces JO Bulletin of Bryansk state technical university AU Kurnosov, N.E. AU Tarnopol'skiy, A.V. AU Nakashidze, Y.Y. PY 2021 IS 2021 PB Bryansk State Technical University