How to get high quality boiler tubes?

2017-12-26

Boiler tubes, also called heat exchanger tubes, are seamless, alloyed steel tubes developed for use at extreme temperatures and pressures. They are primarily used in power plants and petrochemical plants and have a lifecycle of up to 25 years.

Why use boiler tubes?
One of the tubes in a boiler that carry water (water-tube boiler) to be heated by the high-temperature gaseous products ofcombustion or that carry combustion products (fire-tube boiler) to heat the boiler water that surrounds them.

Where are boiler tubes used?
Boiler tubes are used in:
Fire-tube boiler, a type of boiler in which hot gases from a fire pass through one or more tubes running through a sealed container of water.
Water-tube boiler, a type of boiler in which water circulates in tubes heated externally by fire.

Boiler tubing is used in these industries:

Steam Boilers
Power Generation
Fossil Fuel Plants
Electric Power Plants
Industrial Processing Plants
Cogeneration Facilities

Application: For high, middle, low pressure boiler and pressure purpose
Production Standard, Grade, Steel No:
ASTM A178 Grade A, C, D
ASTM A192
ASTM A210 GradeA-1, C
BS3059-Ⅰ 320 CFS
BS3059-Ⅱ 360, 440, 243, 620-460, 622-490, S1, S2, TC1, TC2
EN10216-1 P195TR1/TR2, P235TR1/TR2, P265TR1/TR2
EN10216-2 P195GH, P235GH, P265GH, TC1, TC2
DIN17175 ST35.8, ST45.8
DIN1629 ST37.0, ST44.0, ST50.0
JIS G3454 STPG370, STPG410
JIS G3461 STB340, STB410, STB440
GB5310 20G, 15MoG, 12CrMoG, 12Cr2MoG, 15CrMoG, 12Cr1MoVG, 12Cr2MoWVTiB
GB3087 10, 20

Delivery Condition:
Annealed, Normalized, Normalized and Tempered

Inspection and Test:
Chemical Composition Inspection, Mechanical Properties Test (Tensile Strength,Yield Strength, Elongation, Flaring, Flattening, Bending, Hardness, Impact Test), Surface and Dimension Test,No-destructive Test, Hydrostatic Test.

High pressure boiler tube hardness testing should take into account its mechanical properties, which is related to stainless steel as raw material for the deformation, such as punching, cutting processing performance and quality.

Therefore, all of the high-pressure boiler tubes need to conduct mechanical tests. Mechanical performance testing method is mainly divided into two kinds, one kind is tensile test, the other kind is usually hardness test.

Tensile test is the high pressure boiler tube sample, high pressure boiler tube tend to sample to the fracture on tensile testing machine, mechanical properties and determination of one or more, usually only determination of tensile strength, yield strength, break elongation, and reduction of area. Tensile test is the most basic mechanical properties of metallic materials testing methods, almost all of the metal material, as long as the requirements of the mechanical properties of the high pressure boiler tube, the provisions of the tensile test. Especially those appearance and high pressure boiler tube is not good for the material of hardness test, tensile test became the only means of mechanical properties testing.

Surface treatment:
Oil-dip, Varnish, Passivation, Phosphating, Shot Blasting

ASTM A179 Heat Exchanger Tubes

ASTM A179/A179M, ASME SA179/SA179M is the standard applicable to Seamless cold drawn low carbon steel heat exchanger tubes.

Seamless cold drawn low carbon steel heat exchanger tubes.

Chemistry Composition:

C, %	Mn, %	P, %	S, %
0.06-0.18	0.27-0.63	0.035 max	0.035 max

Mechanical Properties:

Tensile Strength, MPa	Yield Strength, MPa	Elongation, %	Hardness, HRB
325 min	180 min	35 min	72 max

Outside Diameter & Tolerance

Outside Diameter, mm	Tolerance, mm
3.2≤OD＜25.4	±0.10
25.4≤OD≤38.1	±0.15
38.1＜OD＜50.8	±0.20
50.8≤OD＜63.5	±0.25
63.5≤OD＜76.2	±0.30
76.2	±0.38

Wall thickness & Tolerance

Outside Diamter, mm	Tolerance, %
3.2≤OD＜38.1	+20/-0
38.1≤OD≤76.2	+22/-0

Length: 5800mm; 6000mm; 6096mm; 7315mm; 11800mm; and so on.
Max length: 27000mm, also U bending can be offered.

Characteristics of boiler tubes:

Small diameter high-pressure boiler tube surface defects that affect the quality, mainly due to waste generation.

Boiler tubes often in high temperature and high pressure work, tube smoke and water at high temperature steam oxidation and corrosion effects will occur, thus requiring durable steel with high strength, high oxidation resistance, and good organizational stability, high pressure boiler tube in addition to chemical composition and mechanical properties, hydrostatic testing done by the root, to be flaring, flattening test. Steel to heat treatment delivery. In addition, the finished steel microstructure, grain size, there are certain requirements decarburization.

High-pressure boiler tubes are seamless steel tube categories. Seamless same manufacturing method, but used in the manufacture of steel tube, there are strict requirements. Often in high-pressure boiler tubes at high temperature and pressure conditions of use, the tube under the effect of high temperature gas and water vapor, oxidation and corrosion will occur. Require durable steel with high strength, high resistance to oxidation corrosion, and have good organizational stability.

High-pressure boiler tube is mainly used to manufacture high-pressure and high pressure boiler superheater tubes, reheater tubes, windtube, the main steam tube. High-pressure boiler tubes for low and medium pressure boiler (working pressure is generally not more than 5.88Mpa, working temperature below 450 ℃) of heating surface tubes; used for high-pressure boilers (above 9.8Mpa working pressure in general, the working temperature of 450 ℃ ~ 650 ℃ between) the heating surface tubes, economizer, superheater, reheater, petrochemical industrial tube.

Grade 20G Seamless Steel Boiler tube is applicable to seamless tubes for making steam boiler whose pressure is high or higher and seamless tubes used as tubelines.

20G seamless steel tube is a high-quality carbon structural steel, boiler material, the carbon content of 0.17-0.24%, tensile strength of 410Mpa, yield point 230-250Mpa. Is our main production of steel, we can provide 20G Seamless tube with high quality and comp.

Chemical Compositions(%) of GB5310 20G：

Chemical elements	Data
Carbon	0.17-0.24
Silicon	0.17-0.37
Manganese	0.70-1.00
Phosphorus(max)	0.03
Sulfur(max)	0.03
Chromium(max)	0.25
Molybdenum(max)	0.15
Cuprum(max)	0.2
Nickel(max)	0.25
Vanadium(max)	0.08

Mechanical Properties of GB5310 20G：

Properties	Data
Yield Strength (Mpa)	≥415
Tensile Strength (Mpa)	240
Elongation (%)	22

The W.T. tolerance of GB5310 20G：

W.T.(S)		Tolerance of W.T.
<3.5		+15%(+0.48mm min)
		-10%(+0.32mm min)
3.5-20		+15%,-10%
>20	D<219	±10%
	D≥219	+12.5%,-10%

Additional Condition

UT(Ultrasonic examination), AR(As Hot Rolled only), TMCP(Thermal Mechanical Control Processing), N(Normalized), Q+T(Quenched and Tempered),Z Direction Test(Z15,Z25,Z35), Charpy V-Notch Impact Test, The Third Party Test (such as SGS Test), Coated or Shot Blasting and Painting.

GB5310 20G boiler steel tube Application

GB5310 20G seamless steel tubes are mainly used for pressure vessels, machinery, pipe fittings, oil and chemical industry.

GB5310 20G boiler tube Other Name

GB5310 20G boiler steel tube, 20G boiler steel tube, 20G boiler tube.

Source: China Boiler Tubes Manufacturer – Yaang Pipe Industry Co., Limited (www.pipelinedubai.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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