Patent ID: 7057137

Claim:
A weld bead geometry control system for the orbital welding of two flow elements or flow systems held in abutment comprising: a chamber, said chamber having an inlet, an outlet, and a pressure port, said chamber being in fluid communication with a second flow element, said second flow element being held in abutment with a first flow element forming a joint; a positive internal purge from a source flowing from said first element, through said second flow element, to said chamber; a first pressure sensor; a second pressure sensor; said second pressure sensor being in pressure communication with said chamber through said pressure port, said second pressure sensor sensing the pressure of said positive internal purge in said chamber; a proportional valve, said proportional valve having an orifice having an area, said proportional valve sealantly communicating with said chamber outlet, said internal purge exiting said chamber through said orifice; a drive means, said drive means being coupled with said proportional valve, said drive means affecting said area of said orifice, said area affecting the pressure of said positive internal purge in said chamber; a control, data storage, and data processing means, said control, data storage, and data processing means being in data communication with said first pressure sensor and said second pressure sensor, a first and second pressure signals being received from said first and second pressure sensors, said control, data storage, and data processing means being in control communication with said drive means, a control signal being sent to said drive means respondent to said pressure signals; wherein an internal purge pressure target at said joint is entered into said control, data storage, and data processing means, an actual internal purge pressure at said joint being sensed by said first pressure sensor prior to a welding operation, said proportional valve being adjusted to attain said internal pressure target, said a corresponding chamber pressure being sensed by said second pressure sensor, said corresponding chamber pressure being recorded by said control, data storage, and data processing means; and wherein said first pressure sensor is deactivated concurrent to said welding operation, said first flow element and said second flow element being welded in abutment by an orbital welding means; concurrent to said welding operation, said corresponding chamber pressure being maintained in said chamber through the proportionate control of said proportional valve for the purpose of affecting the geometry of a weld bead while in the molten state.