Abstract: A pipe recovery circulation valve for open hole drilling, which includes a valve body attachable intermediate sections of drill string for normally allowing flow therethrough to the drill bit. The valve further includes a fluid flow means where upon activation directs fluid flow exterior to the valve body, a first main sleeve slideable within the bore of the valve body moveable between a first position wherein the fluid flow means prevents fluid flow exterior to the valve body; and a second position wherein the fluid flow means is activated to allow flow exterior to the valve body. An upper retainer sleeve is fixed within the valve body, which includes a spring for allowing the main sleeve to move between the first and second positions against the bias of the spring. A spring loaded detent pin is provided for maintaining a main sleeve in the second position for allowing fluid flow exterior to the valve body.

Abstract: A pipe recovery circulation valve for open hole drilling, which includes a valve body attachable intermediate sections of drill string for normally allowing flow therethrough to the drill bit. The valve further includes a fluid flow means where upon activation directs fluid flow exterior to the valve body, a first main sleeve slideable within the bore of the valve body moveable between a first position wherein the fluid flow means prevents fluid flow exterior to the valve body; and a second position wherein the fluid flow means is activated to allow flow exterior to the valve body. An upper retainer sleeve is fixed within the valve body, which includes a spring for allowing the main sleeve to move between the first and second positions against the bias of the spring. A spring loaded detent pin is provided for maintaining a main sleeve in the second position for allowing fluid flow exterior to the valve body.