PLUG COCK Russian patent published in 1999 - IPC

FIELD: plug cocks for shutting-off flow of working fluid and equalizing pressure in both chambers located at ends of plug. SUBSTANCE: plug cock has body with passage for flow of medium through it, two chambers and taper bore which intersects the above-mentioned passage. Cock includes also conical plug with outer surface, larger end face directed towards one chamber and lesser end face directed to other chamber. Plug is fitted in bore for turning and shutting-off passage when cock is in closed position. Plug is provided with straightway hole and passage. Straightway hole is located for communication with passage when cock is in Open position. Passage is isolated from straightway hole of plug and is used to connect larger and lesser end faces of plug for equalizing the pressure in both chambers located at end faces of plug. Rod is made separately from plug and is kinematically linked with it for turning. Passage is provided with check valve for change of pressure and formation of respective flow in way from larger end face of plug to its lesser end face, thus excluding abrupt shock wave at larger end face of plug which is likely to force plug into bore causing its seizure. EFFECT: enhanced reliability of shutting-off. 5 cl, 13 dwg