Electric Resistance Weld (ERW) Standard Pipe and Line Pipe Manufacturing

Electric Resistance Weld (ERW) Manufacturing Process at McKeesport, PA - 8.625" to 20" O.D.

Coil Feed Ramp	First Forming Section	Fin Pass Section
Coils are removed from storage and placed on a feed ramp. Here each coil is positioned on the center line of the mill and fed into the uncoiling unit. The leading edge feeds into the pinch rolls preceding the flattener. An electrically operated shear cuts off the end of each coil so that the coils can be welded together to form a continuous strip.	The first forming section, composed of breakdown strands, begins the transformation of the strip from flat steel to a round pipe section. The roll transition section receives the product from the first forming section and continues the "rounding-up" process.	The section of the forming rolls finishes the rounding process and contours the edges of the strip for welding.


High Frequency Welder	In-Process Weld Non-Destructive Inspection	Seam Normalizer
The High Frequency Welder heats the edges of the strip to approximately 2600ºF at the fusion point location. Pressure rolls then squeeze the heated edges together to form a fusion weld.	After welding, the weld is inspected by independent non-destructive inspection units.	Here the weld area is subjected to the proper post-weld treatment as metallurgically required to remove welding stresses and produce a uniform normalized grain structure.


Sizing Mill	Flying Cut-Off	Hydrostatic Testing
Here the pipe passes through the sizing mill with idler side-closing rolls between the strands. This process sizes the pipe to proper outside diameter and straightens the pipe at the same time.	As the continuous length moves down the mill, the flying cut-off cuts a designated length of pipe without interrupting continuous product flow of the mill.	Each length of pipe is subjected to a hydrostatic test as a strength and leak check.


Straightening	Non-Destructive Inspection	Cut-Off Facilities
Any bow in the pipe is now removed by a series of horizontal deflection rolls.	The pipe now enters the finishing floor where the weld is ultrasonically inspected and the pipe body is examined by electromagnetic means.	This facility provides test barrels as required and cuts out defects detected by nondestructive inspection.


Facing and Beveling	Final Inspection
Carbide tools cut the desired end finish on the pipe.	A final visual inspection is given the pipe prior to computerized weighing and measuring in preparation for stenciling, loading and shipping.

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