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Introduction: multiple reverse circulation valve is an internal pressure switch operation can be repeated reverse circulation valve. By pressing a certain number of internal operating open and closed by a positive cycle heavy. Because of its flexibility, can be used in a variety of jobs; used as a liquid cushion replace valve; when you open for the treatment solution, acidification and testing process in off valve; fluid circulating inside the tube out; also used to go down during the course of pipe internal pressure test. How it works: When the tool opens, through the inner pipe string into the fluid from annulus a way to shut down. Lower joint has four circulation space, when the fluid through these holes, the tool inner pressure increases, forcing the mandrel moves to the bottom dead center. Will achieve a re-closure, the valve annulus velocity on the size of the non-response, can not be achieved by reverse circulation weight off. |