ИСТИНА

FIELD: mechanical engineering. SUBSTANCE: sealing unit has closing rings arranged in fitting body bore and set of sealing rings manufactured from expanded graphite and positioned between closing rings so as to embrace in sealing relation sealable surfaces of stem and fitting body bore. Closing rings are made in the form of multilayer annular cylinder defined by expanded graphite foil coils and reinforced with coils of metal foil, for instance stainless steel or copper foil. Metal foil coils are enclosed between expanded graphite foil coils. Rigidity of metal foil coils is less than that of expanded graphite foil coils. Multilayer annular cylinder has corrugated structure and it may be completely or partially reinforced. EFFECT: increased efficiency and enhanced reliability in operation. 4 cl, 6 dwg