Product line encopassing seamless pipe and welded pipes, including butt welded pipe, electric resistance welded (ERW) pipe, UOE pipe, and spiral welded pipe.

Manufacturing facilities for pipe and tubes production 

Kind		Line	Available size (mm)			Remarks
			OD	Wall thickness	Length
Seamless pipe		Small diameter seamless pipe mill	25.4– 177.8	2.3–40.0	22 000	Mannesmann piercing/ Mandrel mill
		Medium diameter seamless pipe mill	177.8– 426.0	5.1–65.0	13 500	Mannesmann piercing/ Plug mill
Welded pipe	UOE	Chiba UOE pipe mill	508.4–1 625.6	6.4–44.5	18 300
		Fukuyama UOE pipe mill	406.4–1 422.4	6.0–50.8	18 300	External and internal coating facility
	Spiral	Spiral pipe	600.–2 540	6.0–30.0	35 000
	Electric resistance welded pipe	Small diameter ERW pipe mill (3”)	28.6– 76.4	0.6–10.0	18 000
		Small diameter ERW pipe mill (6”)	60.5– 168.3	0.6–10.0	18 000
		Small diameter ERW pipe mill (4”) HISTORY	21.3– 114.3	1.8–12.7	16 000
		Large diameterERWpipe mill (26”)	318.5– 660.4	4.0–23.8	20 000
			250  250	6.0–25.0	18 000	For square pipes
		24” ERW mill	177.8– 609.6	3.2–19.1	18 500	External coating facility
			200  200	4.5–22.0	18 000	For square pipes
	Butt welded pipe	Butt weld mill	21.7– 114.3	2.8– 4.5	7 000	Plastic lining facility

Seamless Pipes and Tubes

Central steel has two seamless pipe manufacturing lines, the small-diameter seamless pipe mill using the Mannesmann piercing/mandrel mill  process  and the medium-diameter  seamless  pipe  mill  using  the Mannesmann piecing/plug mill process. The small- diameter mill produces pipes and tubes with outer diameters up to 177.8 mm (5”), while the medium-diameter mill produces products with outer diameters from 177.8 mm (5”) to 426.0 mm (16”).

High Cr seamless steel pipes used in oil country tubular goods (OCTG) and boiler tubes are one of central steel’s main product lines, and the company has a high level of know-how in rolling technology for these prod- ucts. In the past, seamless pipes and tubes of high Cr  alloy steel and stainless steel  were  generally  produced by piercing using a hot extrusion process, followed by rolling. central steel was the first steel maker in the world   to succeed in obtaining stable product quality in these products in manufacturing by the Mannesmann  pierc- ing process. These products were realized for the first time as a result of improvement in the properties of the materials by heavy processing in the slab stage, in com- bination with the establishment of various pipe rolling technologies, including billet temperature control during pipe rolling, optimization of piercing conditions, optimi- zation of the pass schedule in mandrel rolling).The seamless pipe mill also has processing equip-ment for production of threaded joints for OCTG.

Welded Steel Pipes and Tubes
As manufacturing facilities for ERW pipes and tubes, central has a four ERW lines. These facilities each have distinctive features, giving the company a system for manufacturing steel pipes and tubes by the optimum process corresponding to the application.

The 26” line at Chita Works produces ERW pipes having the largest outer diameter in the world. With the manufacture of linepipe using this feature as one of its strong points, central steel has commercialized extra-heavy wall ERW linepipes and conductor casings as substitutes for the conventional UOE products. To realize the same strength, toughness, and weldability as in UOE pipe, in these products, the composition design of the hot rolled steel sheet used in the ERW pipe was optimized and the cooling capacity of the hot rolling line was strengthened.