Weld seam finding and marking systems and methods for tubular goods

A method of finding and marking the longitudinal weld seam (S) of one or more longitudinally welded tubular members (P) using a marking assembly (260) comprising an adjustable iris rotor plate (104), the method comprising:

• (a) feeding one or more of the longitudinally welded tubular members (P) serially into the longitudinal weld seam detection assembly (LWSDA, 2) and the marking assembly (260);
• (b) determining an initial position of the longitudinal weld seam (S) using the longitudinal weld seam detection assembly (LWSDA, 2);
• (c) transmitting a first signal indicating the initial position of the longitudinal weld seam (S) to a computer, the computer in turn sending a second signal to the marking assembly (260) to rotate the marking assembly (260) clockwise or counterclockwise to position one of the one or more marking heads (116) above the longitudinal weld seam (S);
• (d) detecting variations in magnetic field produced by the longitudinal weld seam (S) of the one or more longitudinally welded tubular members (P);
• (e) transmitting one or more weld seam detection signals to the computer, the computer programmed to accept longitudinal weld seam detection signals transmitted from the one or more sensors (20) and convert the longitudinal weld seam detection signals into positioning information for the marking assembly (260) to mark the longitudinal weld seam (S);
• (f) transmitting a second signal to rotate the marking assembly (260) to a position where one of the positioned marking head (116) can mark the longitudinal weld seam (S) at a second position;
• (g) transmitting a third signal to initiate the positioned marking head (116) of the marking assembly (260) to mark the LWTM (P) on the outer surface (22) with at least one mark (M) at the second position of the longitudinal weld seam (S) of the LWTM (P) in accordance with the one or more longitudinal weld seam detection signals;
• and
• (h) repeating steps (d)-(g) marking portions of the longitudinal weld seam (S) of the LWTM (P) along substantially its entire length using the one or more marking heads (116).

A marking assembly (260) configured to mark a longitudinal weld seam (S) of longitudinally welded tubular members (LWTM (P)) on an outer surface (22) with one or more marks (M) using one or more marking heads (116) to indicate a location of the longitudinal weld seam (S) of the LWTM (P) in accordance with longitudinal weld seam detection signals, the marking assembly (260) comprising:

• (i) an adjustable iris rotor plate (104) having a central passage (105) and one or more arcuate slots (110);
• (ii) a drive plate (106) also having a central passage substantially coincident with the central passage (105), the drive plate (106) comprising one or more U-shaped support brackets (120) configured to support and guide the adjustable iris rotor plate (104) when the adjustable iris rotor plate (104) is moved clockwise or counterclockwise to accommodate for LWTM (P) of different diameters;
• and
• (iii) a center stator plate (108) also having a central passage substantially coincident with the central passage (105), the center stator plate comprising one or more marking heads (116) slidably secured thereto by respective rails (138),
• the drive plate (106) further comprising gearing, and the marking assembly (260) further comprising a drive wheel having gearing mating with the gearing of the drive plate (106), the drive wheel configured to be actuated to move the marking assembly (260) clockwise or counterclockwise in response to a signal from a computer, the computer receiving signals from sensors that are detecting position of the longitudinal weld seam (S).