Patent ID: 7048079

Claim:
A sub-assembly for use in a mud saver valve, comprising: a spear having first and second ends, said spear having first and second fluid chambers, the first said chamber having a given internal diameter and the second said chamber having sidewalls around said second chamber and having an internal diameter less than said given internal diameter, the said first end of said spear having internal threads and being open for receiving fluids into said first chamber and the second end of said spear being shaped and sized to accommodate a wireline overshot to remove the spear from a mud saver valve assembly, said first fluid chamber being in fluid communication with said second fluid chamber, and having a first truncated, inverted cone valve seat between said first and second fluid chambers, said first and second fluid chambers being in fluid communication with the annulus surrounding said spear through at least one portal through the said sidewalls of the said second chamber of said spear, said second chamber further having a cone shaped end distal from said first truncated, inverted cone valve seat; a fluid diverter valve having a generally cylindrical body, and having first and second ends, and a fluid passageway between the first and second ends of said fluid diverter valve, the first end of said diverter valve having a given external diameter and a second truncated, inverted cone valve seat for receiving a second cone valve, and the second end of said diverter valve having an external diameter greater than the given external diameter of the first end of said diverter valve, said diverter valve having external threads between said first and second ends of said diverter valve; and a diverter valve stem having back-to-back, first and second cone valves, said second cone valve being angled to seat against the said second seat of said fluid diverter valve to substantially prevent a fluid flow in a first direction, said first cone valve having an apex, and having a linear extension from its apex, said linear extension having a cone shaped end distal to said apex of said first cone valve and a given length for allowing said first cone valve to move in close proximity to said first truncated, inverted cone valve seat, in response to a fluid flow in a second direction, and for preventing said first cone valve from seating against the first seat in said spear, wherein the prevention of seating between the first cone valve and the first seat is, at least in part, due to the cone shaped end of said linear extension contacting the cone shaped end of said second chamber, and wherein said moving of first cone valve within close proximity to said first truncated, inverted cone valve seat allows the pressure and other parameters of at least one downhole fluid to be measured, and wherein said diverter valve stem is located within the first fluid chamber of said spear and said diverter valve is threaded into the interior of said spear.