GATE Russian patent published in 2008 - IPC B01L3/02 F16K5/04 

FIELD: engines and pumps.

SUBSTANCE: invention relates to devices for regulation of feeding a liquid or gas in the pipeline and can be used in labware, for example, in burets. The shut-off device incorporates a coaxial pair of pipes wherein the clearance of an inner pipe is stopped by a partition. On one or both sides of the said partition, the inner pipe wall has, respectively, one or two holes. Here, the outer pipe is arranged to rotate about the inner pipe. A recess of variable depth, its section shape approximating to that of a comma, is made on a limited length of the said outer tube inner surface at the level of the aforesaid hole (or holes).

EFFECT: higher reliability and better performances.

4 dwg