CHECK VALVE Russian patent published in 1998 - IPC

FIELD: shutting-off return flow of liquid in pipe lines of large diameters. SUBSTANCE: check valve has body and swivel disk mounted in body on shaft; this disk divides flow section of body into inlet and outlet cavities. Piston of hydraulic drive is connected with shaft and disk by means of lever. Cavity of hydraulic drive is brought in communication with inlet cavity of body by means of pipe line 10 and with outlet cavity of body by means of pipe line 12. End section of pipe line 10 is bent towards forward flow. End sections of pipe lines are fitted with heads having passages in form of contractions changing to diffusers. One head works as ejector on return flow of medium. Other head works as ejector on forward flow of medium. EFFECT: increased resultant force on piston of hydraulic drive and enhanced efficiency of its operation. 6 dwg