Seamless tube lines

Seamless steel pipe rolling lines：

Seamless steel pipe is divided into two types, hot-rolling & cold-rolling (cold-drawing) seamless steel pipe, including low-alloy steel pipe, stainless steel pipe, medium-pressure boiler steel pipe, high-pressure boiler steel pipe, geological steel pipe and other steel pipes.

The outer diameter of hot-rolled seamless tube is generally greater than 32mm, wall thickness from 2.5mm to 75mm; for cold-rolled seamless pipe, the outer diameter can be as small as 6mm, and thickness to 0.25mm. For thin-walled tubes, the outer diameter can be as small as 5mm, with thickness less than 0.25mm. Cold-rolled pipe has higher precision than hot-rolled pipe.

The raw material for seamless steel pipe is round bar. Round bar is cut to fixed length by cutting machine, and then transferred to reheating furnace for heating at about 1200℃. After heated, it is transferred into cone roll piercer for piercing. This piercer has high production efficiency, good product quality, greater expanding/piercing, and it can pierce variable steel grade. After piercing, the round billet is skew-rolled, continuous rolled, and extruded by rolling mill, and then for extracting and sizing, after sizing. Then, it runs into cooling tower to be cooled, and to straightening machine to be straightened. At last, the pipe is delivered by conveyor to metal flow detector (or hydraulic testing) for internal inspection.

Hot-rolled seamless steel pipe process:

Round bars → Reheating furnace → Piercer → Rolling mill → Extractor → Sizing (reducing) → Cooling → Hollow billet→ Straightening machine → Hydraulic testing (flaw detector) → Marking (labeling) → Warehouse

Cold-rolled seamless steel pipe process:

Round bars → Reheating furnace → Piercer → Heading machine → Quenching → Pickling → Oil coating (coppering)→ Multi-passes cold rolling (or drawing) → Hollow billet → Thermal treatment → Straightening machine→ Hydraulic testing (or flaw detector) → Marking (labeling) → Warehouse

Type

Main materials

Standards

Spec.

Application

Alloy pipe

Cr5Mo(P5/T5, STFA25);

15CrMo(P11,

P12, STFA22)

13CrMo44, 12Cr1MoV;

P22(10CrMo910);

T91/P91, P9/T9;

GB5310-2008;

ASTM A335/A213;

ASME SA335;

DIN17175;

JISG3467;

JISG3458; CNB-9

∮14-508×2-50mm

For high temperature and high pressure resistant, low temperature resistant, or corrosion resistant pipelines in oil, chemical, electrical, and boiler industries

Pipe for High pressure boiler

20G, 12Cr1MoVG,

B, 15CrMoG, ST45.8/Ⅲ

GB5310-2008

ASTM A106

DIN17175

∮14-824×2-80mm

For high temperature and high pressure resistant fluid transfer container or pipelines of boilers in power plant and nuclear power plant

Petroleum cracking pipe

10, 20, 16Mn, 15CrMo

GB9948-2006

∮19-530×2-30mm

For pipelines of boilers in oil refinery, of heat exchanger, and of fluid transportation

Pipe for fertilizer equipment

10, 20, 16Mn, 12Cr2Mo

GB6479-2000

∮18-325×2-35mm

For high temperature and high pressure fluid pipeline of fertilizer equipment

Pipe for low and medium pressure boilers

20

GB3087-2008

∮25-426×2.5-30mm

For pipelines of low and medium pressure fluid transportation for industrial boiler and domestic boiler

Fluid pipe

10, 20, Q345B, STPG370

GB/T8163-2008

∮10-660×1.5-40mm

For fluid transportation pipelines in projects and for heavy-duty equipment

Structural pipe

10, 20, 35, 45, 40Cr, Q345B

GB/T8162-2008

∮10-530×1.5-60mm

For common structure and mechanical structure

Line pipe

B, X42, X52PSLII

ASTM A106/A53;

API 5L

∮10-610×1.5-35mm

For gas, water and oil transportation in oil and natural gas industry

Pipe for hydraulic service

27SiMn

GB/T17396-1998

∮95-245×9-30mm

For manufacture of hydraulic support, cylinder and column for mining

Pipe for watercraft

410I, 410II;

410III, 410G

GB/T5312-2009

∮18-530×3-20mm

For pressure pipes (pressure grade I & II) used in watercraft boilers and overheater, etc

Oil pipe

J55, K55, N80I, N80Q, C90, C95, T95, P110, Q125

API 5CT;

SY/T6194-1996

∮60-114×4-12mm

For oil transportation from oil deposit to the ground by means of oil pumping unit

Driller pipe

E75, X95, G105, S135

API 5D;

SY/T5987-1994

∮60-139×6-13mm

For oil and gas well drilling

Pipe sleeve

J55, K55, N80I, N80Q, C90, C95, T95, P110, Q125

API 5CT;

SY/T6194-1996

∮114-340×4-13mm

For oil and gas well wall support
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