CHECK VALVE Russian patent published in 2010 - IPC F16K15/04 F04D13/10 E21B34/00 

FIELD: machine building.

SUBSTANCE: proposed check valve comprises body with top and bottom coupling threads to allow the valve to be connected to tuning string. Movable element has through holes. Coupling serves to adjust spring contraction. Protective seal is pressed by plug. Said moving element represents a stepwise barrel that can move axially in the guides and be aligned in through holes of coupling and plug, and is furnished with axial through stepwise orifice. At the joints of different diametres a chamfer is made to make a seat for shut-off element. The latter represents a ball moving inside larger diametre hole.

EFFECT: reduced costs of additional washing and repair.

3 dwg, 6 cl