China Professional China Boiler, Boiler Tube Manufacturer and Supplier

Professional China Boiler, Boiler Tube

Short Description:

High-quality carbon structural steel, alloy structural steel, and stainless heat-resistant steel seamless steel pipe for high-pressure and above steam boiler pipes in GB/T5310-2007 standard. Material mainly is Cr-Mo alloy and Mn Alloy, Such as 20G, 20MnG, 20MoG, 12CrMoG, etc

Payment: 30% deposit, 70% L/C or B/L copy or 100% L/C at sight

Min.Order Quantity: 1 PC

Supply Ability: Annual 20000 Tons Inventory of Steel Pipe

Lead Time: 7-14 days if in stock, 30-45 days to produce

Packing: Black Vanishing, bevel and cap for every single pipe; OD below 219mm need to pack in bundle, and each bundle no exceed 2 tons.

Send email to us Download as PDF

Product Detail

Product Tags

Our company specializes in exporting various steel pipes Boiler Pipes, Boiler steel pipes, boiler steel tubes, boiler tubes, China Boiler. Many trade novices will encounter problems when quoting, for example difference between steel actual weight and theoretical weight. Let me answer this question for everyone.

1. Theoretical weight of steels

The theoretical weight of steels is obtained by calculating nominal dimensions and density (which is called specific weight in the past). This is directly related with the steel length, the cross section area, and the allowable size deviation. Because of the allowable deviation in the process of manufacturing, the calculated theoretical weight is somehow different from the actual value, and the theoretical value is only for reference while estimating。

2. Actual weight of steel

Actual weight of steel refers to the weight obtained by actual weighting (with a scale). The actual weight is more accurate than the theoretical weight.

3. Methods for calculating weight of steel

KG/M=(OD-WT)*WT*0.02466

Overview

Application

It is mainly used to make high-quality carbon structural steel, alloy structural steel and stainless heat-resistant steel seamless steel pipes for high pressure and above steam boiler pipes.

Mainly used for high pressure and high temperature service of boiler(Superheater tube, reheater tube, air guide tube, main steam tube for high and ultra high pressure boilers). Under the action of high temperature flue gas and water vapor, the tube will oxidize and corrode. It is required that the steel pipe has high durability, high resistance to oxidation and corrosion, and good structural stability.

Main Grade

Grade of high-quality carbon structural steel: 20g、20mng、25mng

Grade of alloy structural steel: 15mog、20mog、12crmog、15crmog、12cr2mog、12crmovg、12cr3movsitib, etc

Grade of rust-resistant heat-resistant steel: 1cr18ni9 1cr18ni11nb

Chemical Component

Grade	Quality Class	Chemical Property
		C	Si	Mn	P	S	Nb	V	Ti	Cr	Ni	Cu	Nd	Mo	B	Als”
		不大于														不小于
Q345	A	0.20	0.50	1.70	0.035	0.035				0.30	0.50	0.20	0.012	0.10	—	—
	B				0.035	0.035
	C				0.030	0.030	0.07	0.15	0.20							0.015
	D	0.18			0.030	0.025
	E				0.025	0.020
Q390	A	0.20	0.50	1.70	0.035	0.035	0.07	0.20	0.20	0.3。	0.50	0.20	0.015	0.10	—	—
	B				0.035	0.035
	C				0.030	0.030										0,015
	D				0.030	0.025
	E				0.025	0.020
Q42O	A	0.20	0.50	1.70	0.035	0.035	0.07	0.2。	0.20	0.30	0.80	0.20	0.015	0.20	—	—
	B				0.035	0.035
	C				0.030	0.030										0.015
	D				0.030	0.025
	E				0.025	0.020
Q46O	C	0.20	0.60	1.80	0.030	0.030	0.11	0.20	0.20	0.30	0.80	0.20	0.015	0.20	0.005	0.015
	D				0.030	0.025
	E				0.025	0.020
Q500	C	0.18	0.60	1.80	0.025	0.020	0.11	0.20	0.20	0.60	0.80	0.20	0.015	0.20	0.005	0.015
	D				0.025	0.015
	E				0.020	0.010
Q550	C	0.18	0.60	2.00	0.025	0,020	0.11	0.20	0.20	0.80	0.80	0.20	0.015	0.30	0.005	0.015
	D				0.025	0,015
	E				0.020	0.010
Q62O	C	0.18	0.60	2.00	0.025	0.020	0.11	0.20	0.20	1.00	0.80	0.20	0.015	0.30	0.005	0.015
	D				0.025	0.015
	E				0.020	0.010
Except for Q345A and Q345B grades, the steel should contain at least one of the refined grain elements Al, Nb, V, and Ti. According to the needs, the supplier can add one or more refined grain elements, the maximum value Should meet the requirements in the table. When combined, Nb + V + Ti <0.22% °For Q345, Q390, Q420 and Q46O grades, Mo + Cr <0.30% oWhen each grade of Cr and Ni is used as the residual element, the content of Cr and Ni should not be more than 0.30%; when it needs to be added, its content should meet the requirements in the table or be determined by the supplier and the buyer through consultation.J If the supplier can guarantee that the nitrogen content meets the requirements in the table, the nitrogen content analysis may not be performed. If Al, Nb, V, Ti and other alloy elements with nitrogen fixation are added to the steel, the nitrogen content is not limited. The nitrogen fixation content should be specified in the quality certificate.’When using all aluminum, the total aluminum content AIt ^ 0.020% B

Mechanical Property

No	Grade	Mechanical Property
		Tensile MPa	Yield MPa	Extend L/T	Impect (J) Vertical/ Horizontal	Handness HB
1	20G	410- 550	≥ 245	24/22%	40/27	—
2	20MnG	415- 560	≥ 240	22/20%	40/27	—
3	25MnG	485- 640	≥ 275	20/18%	40/27	—
4	15MoG	450- 600	≥ 270	22/20%	40/27	—
6	12CrMoG	410- 560	≥ 205	21/19%	40/27	—
7	15CrMoG	440- 640	≥ 295	21/19%	40/27	—
8	12Cr2MoG	450- 600	≥ 280	22/20%	40/27	—
9	12Cr1MoVG	470- 640	≥ 255	21/19%	40/27	—
10	12Cr2MoWVTiB	540- 735	≥ 345	18/-%	40/-	—
11	10Cr9Mo1VNbN	≥ 585	≥ 415	20/16%	40/27	≤ 250
12	10Cr9MoW2VNbBN	≥ 620	≥ 440	20/16%	40/27	≤ 250

Tolerance

Wall Thickness and Outter Diameter:

If there is no special requirements, pipe gonna be delivery as norminal outter diameter and norminal wall thickness. As follow sheet

Classification designation	Method of manufacture	Size of pipe			Tolerance
					Normal grade	High grade
W H	Hot Rolled（extrude） pipe	Norminal outter Diameter （D）	<57		士 0.40	±0,30
			57 〜325	SW35	±0.75%D	±0.5%D
				S>35	±1%D	±0.75%D
			>325 〜6。。		+ 1%D or + 5.Take lesser one一2
			>600		+ 1%D or + 7,Take lesser one一2
		Norminal Wall Thickness （S）	<4.0		±\|・丨）	±0.35
			>4.0-20		+ 12.5%S	±10%S
			>20	DV219	±10%S	±7.5%S
				心219	+ 12.5%S -10%S	土 10%S

W-H	Thermal expansion pipe	Norminal outter Diameter (D)	all	±1%D	±0.75%。
W-H	Thermal expansion pipe	Norminal Wall Thickness (S)	all	+ 20%S -10%S	+ 15%S -io%s
W-C	Cold drawn(rolled) Ppipe	Norminal outter Diameter (D)	<25.4	±’L1j	—
			>25.4 〜4()	±0.20
			>40 〜50	\|:0.25	—
			>50 〜60	±0.30
			>60	±0.5%D
		Norminal Wall Thickness (S)	<3.0	±0.3	±0.2
		Norminal Wall Thickness (S)	>3.0	S	±7.5%S

Length:

The usual length of steel pipes is 4 000 mm ~ 12 000 mm. After consultation between the supplier and the buyer, and fill in the contract, it can be delivered steel pipes with a length greater than 12 000 mm or shorter than I 000 mm but not shorter than 3 000 mm; short length The number of steel pipes less than 4,000 mm but not less than 3,000 mm shall not exceed 5% of the total number of steel pipes delivered

Delivery weight：
When the steel pipe is delivered according to the nominal outer diameter and nominal wall thickness or the nominal inner diameter and nominal wall thickness, the steel pipe is delivered according to the actual weight. It can also be delivered according to the theoretical weight.
When the steel pipe is delivered according to the nominal outer diameter and minimum wall thickness, the steel pipe is delivered according to the actual weight; the supply and demand parties negotiate. And it is indicated in the contract. The steel pipe can also be delivered according to the theoretical weight.

Weight tolerance：
According to the requirements of the purchaser, after consultation between the supplier and the purchaser, and in the contract, the deviation between the actual weight and the theoretical weight of the delivery steel pipe shall meet the following requirements:
a) Single steel pipe: ± 10%;
b) Each batch of steel pipes with a minimum size of 10 t: ± 7.5%.

Test Requirement

Hydraustatic Test:

The steel pipe should be tested hydraulically one by one. The maximum test pressure is 20 MPa. Under the test pressure, the stabilization time should be not less than 10 s, and the steel pipe should not leak.

After the user agrees, the hydraulic test can be replaced by eddy current testing or magnetic flux leakage testing.

Nondestructive Test：

Pipes that require more inspection should be ultrasonically inspected one by one. After the negotiation requires the consent of the party and is specified in the contract, other non-destructive testing can be added.

Flattening Test：

Tubes with an outer diameter greater than 22 mm shall be subjected to a flattening test. No visible delamination, white spots, or impurities should occur during the entire experiment.

Flaring Test:

According to the requirements of the purchaser and stated in the contract, the steel pipe with outer diameter ≤76mm and wall thickness ≤8mm can be done flaring test . The experiment was performed at room temperature with a taper of 60 °. After the flaring, the flaring rate of the outer diameter should meet the requirements of the following table, and the test material must not show cracks or rips

Steel Type	Outter diameter flaring rate of steel pipe/%
	Inner Diameter/Outter Diameter
	<0.6	>0.6 〜0.8	>0.8
High-quality carbon structural steel	10	12	17
Structural alloy steel	8	10	15
•The inner diameter is calculated for the sample.