Mud saver valve

Claim 2

Mud saver valve adapted for connection between a kelly and a string of drill pipe comprising a tubular valve body having means at its lower end for making connection to a string of drill pipe and tapered threaded and shouldered means at its upper end for making a rotary shouldered connection to a top sub, a tubular top sub having means at its upper end for making connection to a kelly and tapered threaded and shouldered means at its lower end for making a rotary shouldered connection to said tapered threaded and shouldered means on the valve body, said top sub having a downwardly facing valve seat forming part of a poppet valve, closure means for said poppet valve including a seating portion adapted to engage and seal with the poppet valve seat, said closure means including a stem extending downwardly from said seating portion, said stem including an upper part and a lower part, screw thread means connecting said upper and lower parts of the stem, said stem having a downwardly facing shoulder on the upper part thereof and an upwardly facing shoulder on the lower part thereof, an annular chamber between the stem and body, said chamber having an upwardly facing shoulder, bridge means around said stem overlying said chamber shoulder and said upwardly facing stem shoulder, and spring means disposed around said stem in said chamber and under compression, bearing at its lower end against said bridge and at its upper end against the downwardly facing shoulder on the stem, said bridge being separated from the upwardly facing stem shoulder when the valve is in use but engageable with said shoulder when the top sub is unscrewed.

Claim 3

Valve according to claim 1 wherein the screw thread means connecting the upper and lower parts of the stem is a straight-threaded rotary shouldered connection forming a seal between said stem parts.

Claim 4

Valve according to claim 1 including upper and lower seal means between the tubular valve body and said stem to seal said chamber from other interior portions of the valve, said lower seal means comprising stationary seal means between said bridge and the valve body and slidable seal means between said bridge and said stem.

Claim 5

Valve according to claim 1 including upper and lower seal means between the tubular valve body and said stem to seal said chamber from other interior portions of the valve, said upper seal means comprising seal ring means captured between oppositely facing shoulders on said stem, said stem being partable between the last said shoulders for assembly of said seal ring means.

Claim 6

Valve according to claim 1 including upper and lower seal means between the tubular valve body and said stem to seal said chamber from other interior portions of the valve, at least one of said seal means including unidirectional means sealing preferentially in one direction, and orientation means on the unidirectional sealng means to insure proper assembly thereof.

Claim 7

Valve according to claim 1 wherein the valve seat is formed of sealing material softer than steel.

Claim 8

Valve according to claim 1 wherein the valve seat is separable from the top sub.

Claim 9

Valve according to claim 1 wherein the valve seat is formed by an elastomer tube inserted into the lower end of the top sub and including releasable means for retaining the tube in the sub.

Claim 10

Mud saver valve adapted for connection between a kelly and a string of drill pipe comprising a tubular valve body having means at its lower end for making connection to a string of drill pipe and tapered threaded and shouldered means at its upper end for making a rotary shouldered connection to a top sub, a tubular top sub having means at its upper end for making connection to a kelly and tapered threaded and shouldered means at its lower end for making a rotary shouldered connection to said tapered threaded and shouldered means on the valve body, said top sub having a downwardly facing valve seat forming part of a poppet valve, closure means for said poppet valve including a seating portion adapted to engage and seal with the poppet valve seat, said closure means including a stem extending downwardly from said seating portion, said stem including an upper section, a median section, and a lower section, screw thread means connecting said upper and median section and said median and lower sections of the stem, said stem having downwardly facing shoulders on said upper and median sections thereof and upwardly facing shoulders on said median and lower sections thereof, an annular chamber between the stem and body, the chamber forming portion of said valve body including an upper portion and a lower portion having a smaller diameter than said upper portion, said diameter change occuring below said downwardly facing median stem section shoulder, flange means on said stem sealing against said upper portion of said chamber forming portion of the valve body and being captured between said downwardly facing upper stem section shoulder and said upwardly facing median stem section shoulder, fluid passage means through the side of said valve stem above said flange means, lower seal means on said stem sealing against said lower portion of said chamber forming portion of the valve body, said lower seal means including bridge means around said stem overlying said valve body diameter change portion and said upwardly facing lower stem section shoulder, a sealed annular chamber formed between said flange means and said lower seal means and between the valve stem and valve body, spring means disposed around said stem in said sealed chamber and under compression, said spring means bearing at its upper end against said downwardly facing median stem portion shoulder and at its lower end against said bridge means, said bridge means being separated from the upwardly facing lower stem portion shoulder when the valve is in use but engageable with said shoulder when the top sub is unscrewed, and said flange means and said lower seal means being exposed to drilling mud pressure such that due to the difference in diameter of the flange means and lower seal means a net downward force is exerted on said valve stem.

Claim 11

Mud saver valve adapted for connection between a kelly and a string of drill pipe comprising a tubular valve body having means at its lower end for making connection to a string of drill pipe and tapered threaded and shouldered means at its upper end for making a rotary shouldered connection to a top sub, a tubular top sub having means at its upper end for making connection to a kelly and tapered threaded and shouldered means at its lower end for making a rotary shouldered connection to said tapered threaded and shouldered means on the valve body, said top sub having a downwardly facing valve seat forming part of a poppet valve, closure means for said poppet valve including a seating portion adapted to engage and seal with the poppet valve seat, said closure means including a stem extending downwardly from said seating portion, said stem including an upper section, a median section, and a lower section, screw thread means connecting said upper and median section and said median and lower sections of the stem, said stem having downwardly facing shoulders on said upper and median sections thereof and upwardly facing shoulders on said median and lower sections thereof, an annular chamber between the stem and body, the chamber forming portion of said valve body including an upper portion and a lower portion having a smaller diameter than said upper portion, said diameter change occuring below said downwardly facing median stem section shoulder, flange means on said stem sealing against said upper portion of said chamber forming portion of the valve body and being captured between said downwardly facing upper stem section shoulder and said upwardly facing median stem section shoulder, fluid passage means through the side of said valve stem above said flange means, lower seal means on said stem sealing against said lower portion of said chamber forming portion of the valve body, said lower seal means including bridge means around said stem overlying said valve body diameter change portion and said upwardly facing lower stem section shoulder, a sealed annular chamber formed between said flange means and said lower seal means and between the valve stem and valve body, spring means disposed around said stem in said sealed chamber and under compression, said spring means bearing at its upper end against said downwardly facing median stem portion shoulder and at its lower end against said bridge means, said bridge means being separated from the upwardly facing lower stem portion shoulder when the valve is in use but engageable with said shoulder when the top sub is unscrewed, and said flange means and said lower seal means being exposed to drilling mud pressure such that due to the difference in diameter of the flange means and lower seal means a net downward force is exerted on said valve stem.

Claim 12

Valve according to claim 9 wherein said downwardly facing valve seat is replaceable and separable from the top sub.

Claim 13

Valve according to claim 9 wherein the valve seat is comprised of a tubular body of a material softer than steel which body is inserted into the lower end of the top sub and retained in the sub by releasable means.

Claim 14

Valve according to claim 9 wherein the screw thread means connecting the upper and median stem parts is a tapered-threaded connection and the screw thread means connecting the median and lower stem parts is a straight-threaded rotary shouldered connection forming a seal between said stem parts.

Claim 15

Valve according to claim 9 wherein said lower seal means comprises stationary means between said bridge and the valve body and slidable seal means between said bridge and said stem.

Claim 16

Valve according to claim 9 wherein said flange means comprises seal ring means.

Claim 17

Valve according to claim 9 wherein said flange means and said lower seal means include unidirectional means sealing preferentially in one direction, and orientation means on the unidirectional sealing means to insure proper assembly thereof.