Well cementing valve

摘要

A well cementing valve is shown which includes a tubular mandrel having at least one lateral port and which is adapted to be made in a well tubing string. An external seal ring having a seal region circumscribes the mandrel on one side of the lateral port. An axially movable sleeve valve initially covers the mandrel ports on the mandrel exterior. The sleeve valve has a pressure responsive seal area subject to fluid pressure in the mandrel for moving the sleeve valve. An axially slidable protective sleeve initially surrounds the mandrel and the sleeve valve. A plurality of shear pins connect the protective sleeve to the sleeve valve to restrain the sleeve valve against axial displacement. The pressure responsive seal area on the sleeve valve is operable to apply a shearing load on the pins to permit an axial displacement of the protective sleeve and an opposite axial displacement of the sleeve valve to open the ports.