| 摘要 |
A combination control valve wherein a seal directed towards the valve exterior is achieved by a double gland which straddles a lantern sleeve with an intermediate vent and is pressed axially between the stem and guide for the main valving member by preloaded elastic elements, said guide being held elastically pressed against the differently inclined surface of a shoulder ring retained by circular sectors fitted into the valve body, a series of labyrinths being interposed between said guide and said main valving member, the pilot valving member being of parabolic profile, a bellows elastic seal element being provided between the first seat and the valve body, the trim including a hollow cylindrical structure which is inserted coaxially into an end cavity in the main relying member, is provided with transverse holes arranged offset from corresponding holes in the cavity of the main valving member, and terminates with a parabolic profile.
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