Abstract: A tube shaped sleeve apparatus which includes two cylindrical components adapted to be connected to each other and sections of tubing string by cooperating threads formed at the ends thereof. At spaced intervals in the periphery of the sleeve are a plurality of radial holes or ports and formed in the sleeve bore at opposite ends thereof are stops shoulders. Adapted to be inserted in slidable relation inside the bore of the tubing sleeve is a mandrel which includes a plurality of resilient O-rings or gaskets that are secured in the periphery of the mandrel inside annular grooves formed therein. Formed in the bore of the mandrel and at opposite ends thereof are a second set of stop shoulders. When positioned opposite the holes in the sleeve, the periphery of the mandrel and the gaskets form a tight seal with the wall of the sleeve bore to prevent fluids and gases from the well bore from entering and escaping the tubing sleeve.