FIELD: mechanical engineering; packing of loose materials in valve bags or other bags. SUBSTANCE: after installation of stuffing box 4 impregnated with self-lubricating substances onto machine shaft 5, tightening of stuffing box is carried out using main bush. Then surface of contact of stuffing box and shaft gets hardened with machine idling. In process of service running, hardened surface of stuffing box is case-hardened by particles of loose material. EFFECT: increased operating strength of contact seal. 1 dwg
