Multi-stage pressure control dump valve assembly for torque control operations

Abstract

A “dump” or bypass system for use with fluid-powered tongs utilized to apply torque forces to threaded connections during pipe installation operations. A computer having a data processor monitors and analyzes rotations of, and torque forces applied to, pipe sections being assembled. A pilot-operated relief valve actuates a bypass dump valve. The bypass system operates in “real-time”, quickly and efficiently dumping fluid supplying a power tong—and stopping the application of torque forces on a pipe section—once a predetermined measured torque value is achieved.

What is claimed: 
     
         1 . A fluid pressure bypass assembly for controlling the application of torque to a threaded pipe connection comprising:
 a) a tong unit adapted to impart torque to said threaded connection;   b) a supply conduit adapted to supply hydraulic fluid to an inlet of said tong unit;   c) an outlet conduit adapted to receive hydraulic fluid from an outlet of said tong unit;   d) a bypass conduit extending between said supply conduit and said outlet conduit;   e) a pilot controlled hydraulic valve disposed along said bypass conduit, wherein said pilot controlled hydraulic valve is adapted to shift between a first closed position and a second open position in response to a pneumatic pilot signal;   f) a torque sensor adapted to measure torque applied to said threaded connection by said tong unit; and   g) a computer having a data processor, wherein said computer receives data from said torque sensor and shifts said pilot controlled hydraulic valve from said first position to said second position to bypass said tong unit when said torque sensor measures a preselected torque value.   
     
     
         2 . The fluid pressure bypass assembly of  claim 1 , wherein said torque sensor comprises a load cell. 
     
     
         3 . The fluid pressure bypass assembly of  claim 1 , further comprising a rotary encoder adapted to measure speed, direction and/or rotation of said threaded connection, and wherein said computer receives measured data from said rotary encoder. 
     
     
         4 . A fluid pressure bypass assembly for controlling the application of torque to a threaded pipe connection comprising:
 a) a tong unit adapted to impart torque to said threaded connection;   b) a supply conduit adapted to supply hydraulic fluid to an inlet of said tong unit;   c) an outlet conduit adapted to receive hydraulic fluid from an outlet of said tong unit;   d) a bypass conduit extending between said supply conduit and said outlet conduit;   e) a pilot controlled hydraulic valve disposed along said bypass conduit, wherein said pilot controlled hydraulic valve is adapted to shift between a first closed position and a second open position in response to a pneumatic pilot signal;   f) an air compressor adapted to provide a pneumatic pilot signal to said pilot controlled hydraulic valve;   g) a torque sensor adapted to measure torque applied to said threaded connection by said tong unit; and   h) a computer having a data processor, wherein said computer receives data from said torque sensor and interrupts said pneumatic pilot signal to said pilot controlled hydraulic valve, thereby shifting said pilot controlled hydraulic valve from said first position to said second position and bypassing said tong unit, when said torque sensor measures a preselected torque value.   
     
     
         5 . The fluid pressure bypass assembly of  claim 4 , wherein said torque sensor comprises a load cell. 
     
     
         6 . The fluid pressure bypass assembly of  claim 4 , further comprising a rotary encoder adapted to measure speed, direction and/or rotation of said threaded connection, and wherein said computer receives measured data from said rotary encoder. 
     
     
         7 . The fluid pressure bypass assembly of  claim 4 , further comprising:
 a) a pneumatic supply conduit connecting said air compressor to said pilot controlled hydraulic valve; and   b) a pneumatic control valve disposed along said pneumatic supply conduit, wherein said pneumatic control valve is adapted to shift between a first open position and a second closed position.   
     
     
         8 . The fluid pressure bypass assembly of  claim 7 , wherein said pneumatic control valve is adapted to shift between said first open position and said second closed position in response to an electronic signal from said computer. 
     
     
         9 . The fluid pressure bypass assembly of  claim 8 , wherein said pneumatic control valve comprises a solenoid operated valve.