MULTIPURPOSE BALL VALVE WITH ROTARY MOTION SCREW-IN SUB (VERSIONS) Russian patent published in 2008 - IPC F16K5/06 F16J15/50 F16K37/00 

FIELD: engines and pumps transport.

SUBSTANCE: ball valve comprises a body with a seat and sealing elements, a rotary ball plug with a cylindrical throat, a stem and a stem seal, the stem, its one end being screwed in the ball plug, and the stem seal being made as a rotary motion screw-in sub locked in the valve body by means of a clamping element and a screwed nut and made up of three inter-ground ceramic washers. Two of the one-side ground washers are arranged fixed relative to the valve body. The third (central) movable ceramic is rigidly fixed on the separable stem, the said stem being separated into two parts by screwing it out through the seal. The seals are arranged in the movable washer recesses. The stem has, at least, one through bore designed to communicate the ball plug throat with the measuring instrument.

EFFECT: higher reliability, longer life and expanded performances.

7 cl, 5 dwg