Stainless pipes & tubes

Stainless steel is a versatile material comprised of a steel alloy and a small percentage of chromium — the addition of chromium adds to the material’s corrosion resistance, a trait that earned stainless steel its name. Because stainless steel is also low-maintenance, oxidation resistant, and doesn’t affect other metals it comes in contact with, it is frequently used in a large array of applications, especially in piping and tubing manufacturing.

Stainless Steel Pipe

Stainless steel pipe is one of the more standardized materials in the building and engineering industries.

Stainless steel tube

Stainless steel tube is typically measured by its outer diameter and can be used in a variety of applications including a number of structural applications.

Seamless stainless steel pipe

A seamless pipe, as the name suggests, is a pipe without a seam or a weld-joint.

Stainless Steel welded pipe

Our supply of stainless steel square tube and rectangular tube offerings are available in a wide variety of sizes and wall thicknesses.

Heat resistant stainless steel pipe

The auction is for 6 metre length of prime quality grade 409 stainless steel tubing with a 1.2mm wall thickness x 38.1mm (1 1/2") diameter.

Stainless steel oval pipe

Stainless steel oval tube offered in grades 304 and 316 in a wide choice of sizes.

Stainless square / rectangular Tubes

Our supply of stainless steel square tube and rectangular tube offerings are available in a wide variety of sizes and wall thicknesses.

Bright annealing tube

Bright annealing tube under a reducing atmosphere or in a vacuum protection...

Stainless heat exchanger tube

Stainless heat exchanger tube in an extensive range of austenitic stainless steels, duplex stainless steels

Stainless steel fin tube

Stainless Steel Fin Tubes are processed out of various Grades of both Seamless and Welded Plain Tubes.

Stainless carbon steel composite pipe

The stainless carbon steel composite pipe is made of stainless steel and carbon structural steel.

Material stainless steel grades

Also known as "marine grade" stainless steel due to its increased ability to resist saltwater corrosion compared to type 304. SS316 is often used for building nuclear reprocessing plants.

304/304L Stainless Steel

304 Stainless is a low carbon (0.08% max) version of basic 18-8 also known as 302. Type 302 has 18% chromium and 8% nickel.

316/316L Stainless Steel

Type 316/316L Stainless Steel is a molybdenum steel possessing improved resistance to pitting by solutions containing chlorides and other halides.

310S Stainless Steel

310S Stainless Steel has excellent resistance to oxidation under constant temperatures to 2000°F.

317L Stainless Steel

317L is a molybdenum bearing austenitic chromium nickel steel similar to type 316, except the alloy content in 317L is somewhat higher.

321/321H Stainless Steel

Type 321 is basic type 304 modified by adding titanium in an amount at least 5 times the carbon plus nitrogen contents.

410 Stainless Steel

Type 410 is a martensitic stainless steel which is magnetic, resists corrosion in mild environents and has fairly good ductility.

SA 269

ASTM A269 / A269M Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service

SA 249 Stainless Steel

ASME SA 249 Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes.

904L Stainless steel

904L stainless steel consists of chromium, nickel, molybdenum and copper contents, these elements give type 904L stainless steel excellent properties

Duplex pipes

What is Duplex Stainless Steel?

Duplex Stainless Steel is a type of steel containing the high amount of chromium and minimum amount of nickel. It provides great strength and resistance to corrosive environments.

Duplex 2205 (UNS S31803)

Duplex 2205 (UNS S31803), or Avesta Sheffield 2205 is a ferritic-austenitic stainless steel.

Duplex 2507 (UNS S32750)

Duplex 2507 (UNS S32750) is a super duplex stainless steel with 25% chromium, 4% molybdenum..

DUPLEX UNS S32760

UNS S32760 is described as a super duplex stainless with a microstructure of 50:50 austenite and ferrite.

Comparison table of stainless steel brands of various countries

In order to solve the cumbersome and difficult to remember stainless steel grades, improve the practicability of the brand representation, and the contrast with the international standard grades, China has formulated the "Universal Code System for Steel and Alloy Grades", such as 06Cr19Ni10, corresponding to 304. Different grades of stainless steel have different ingredients, but they all have a national standard. The standards of each country are also different.

The specific standards of each country are as follows:

No	China,GB		Japan	American		Korea	EUR	Indai	Australia	Tai Wan
No	Old	New（07.10）	JIS	ASTM	UNS	KS	BS EN	IS	IS	CNS
Austenitic stainless steel
1	1Cr17Mn6Ni5N	12Cr17Mn6Ni5N	SUS201	201	S20100	STS201	1.4372	10Cr17Mn6Ni4N20	201-2	201
2	1Cr18Mn8Ni5N	12Cr18Mn9Ni5N	SUS202	202	S20200	STS202	1.4373		-	202
3	1Cr17Ni7	12Cr17Ni7	SUS301	301	S30100	STS301	1.4319	10Cr17Ni7	301	301
4	0Cr18Ni9	06Cr19Ni10	SUS304	304	S30400	STS304	1.4301	07Cr18Ni9	304	304
5	00Cr19Ni10	022Cr19Ni10	SUS304L	304L	S30403	STS304L	1.4306	02Cr18Ni11	304L	304L
6	0Cr19Ni9N	06Cr19Ni10N	SUS304N1	304N	S30451	STS304N1	1.4315	-	304N1	304N1
7	0Cr19Ni10NbN	06Cr19Ni9NbN	SUS304N2	XM21	S30452	STS304N2	-	-	304N2	304N2
8	00Cr18Ni10N	022Cr19Ni10N	SUS304LN	304LN	S30453	STS304LN	-	-	304LN	304LN
9	1Cr18Ni12	10Cr18Ni12	SUS305	305	S30500	STS305	1.4303	-	305	305
10	0Cr23Ni13	06Cr23Ni13	SUS309S	309S	S30908	STS309S	1.4833	-	309S	309S
11	0Cr25Ni20	06Cr25Ni20	SUS310S	310S	S31008	STS310S	1.4845	-	310S	310S
12	0Cr17Ni12Mo2	06Cr17Ni12Mo2	SUS316	316	S31600	STS316	1.4401	04Cr17Ni12Mo2	316	316
13	0Cr18Ni12Mo3Ti	06Cr17Ni12Mo2Ti	SUS316Ti	316Ti	S31635	-	1.4571	04Cr17Ni12MoTi20	316Ti	316Ti
14	00Cr17Ni14Mo2	022Cr17Ni12Mo2	SUS316L	316L	S31603	STS316L	1.4404	-02Cr17Ni12Mo2	316L	316L
15	0Cr17Ni12Mo2N	06Cr17Ni12Mo2N	SUS316N	316N	S31651	STS316N	-	-	316N	316N
16	00Cr17Ni13Mo2N	022Cr17Ni13Mo2N	SUS316LN	316LN	S31653	STS316LN	1.4429	-	316LN	316LN
17	0Cr18Ni12Mo2Cu2	06Cr18Ni12Mo2Cu2	SUS316J1	-	-	STS316J1	-	-	316J1	316J1
18	00Cr18Ni14Mo2Cu2	022Cr18Ni14Mo2Cu2	SUS316J1L	-	-	STS316J1L	-	-	-	316J1L
19	0Cr19Ni13Mo3	06Cr19Ni13Mo3	SUS317	317	S31700	STS317	-	-	317	317
20	00Cr19Ni13Mo3	022Cr19Ni13Mo3	SUS317L	317L	S31703	STS317L	1.4438	-	317L	317L
21	0Cr18Ni10Ti	06Cr18Ni11Ti	SUS321	321	S32100	STS321	1.4541	04Cr18Ni10Ti20	321	321
22	0Cr18Ni11Nb	06Cr18Ni11Nb	SUS347	347	S34700	STS347	1.455	04Cr18Ni10Nb40	347	347
Austenitic ferritic stainless steel (duplex stainless steel)
23	0Cr26Ni5Mo2	-	SUS329J1	329	S32900	STS329J1	1.4477	-	329J1	329J1
24	00Cr18Ni5Mo3Si2	022Cr19Ni5Mo3Si2N	SUS329J3L	-	S31803	STS329J3L	1.4462	-	329J3L	329J3L
0Cr18Ni10Ti Iron type stainless steel
25	0Crl3Al	06Crl3Al	SUS405	405	S40500	STS405	1.4002	04Cr13	405	405
26	-	022Cr11Ti	SUH409	409	S40900	STS409	1.4512	-	409L	409L
27	00Cr12	022Cr12	SUS410L	-	-	STS410L	-	-	410L	410L
28	1Cr17	10Cr17	SUS430	430	S43000	STS430	1.4016	05Cr17	430	430
29	1Cr17Mo	10Cr17Mo	SUS434	434	S43400	STS434	1.4113	-	434	434
30	-	022Cr18NbTi	-	-	S43940	-	1.4509	-	439	439
31	00Cr18Mo2	019Cr19Mo2NbTi	SUS444	444	S44400	STS444	1.4521	-	444	444
Martensitic stainless steel
32	1Cr12	12Cr12	SUS403	403	S40300	STS403	-	-	403	403
33	1Cr13	12Cr13	SUS410	410	S41000	STS410	1.4006	12Cr13	410	410
34	2Cr13	20Cr13	SUS420J1	420	S42000	STS420J1	1.4021	20Cr13	420	420J1
35	3Cr13	30Cr13	SUS420J2	-	-	STS420J2	1.4028	30 Cr13	420J2	420J2
36	7Cr17	68Cr17	SUS440A	440A	S44002	STS440A	-	-	440A	440A

Stainless Steel Tube & Pipe Tolerance

In the production process, because the actual size is difficult to meet the nominal pipe size requirement, that is, it is often larger or smaller than the nominal size, so the standard stipulates that there is a difference between the actual size and the nominal size of the stainless steel pipe. A positive difference is called a positive deviation, and a negative difference is called a negative deviation.

Outside diameter (OD), wall thickness and length are three basic parameters in the process of manufacture and distribution for stainless steel tube & pipe, and these parameters have been standardized.

Outer diameter and wall thickness are particularly important, they are not only the basic support for meeting the design requirements of various types of applications such as strength, stiffness and fluid delivery, but also have a decisive influence on the subsequent processing, therefore, standards for stainless steel tube & pipe diameter and wall thickness of the manufacturing accuracy (tolerance) should been standardized.

What is Nominal Pipe Size and Actual Pipe Size

A. Nominal Pipe size: It is the nominal size specified in the standard such ASME B36.10m, ASME B36.19m, the ideal size that users and manufacturers hope to obtain, and the order size specified in the contract.

B. Actual Pipe size: It is the actual size obtained during the production process, which is often larger or smaller than the nominal size. This phenomenon of being larger or smaller than the nominal size is called deviation.

European Standard

European stainless steel tube & pipe standards specify 4 classes outer diameter and wall thickness in percentage or absolute value on the basis of nominal dimension.

Generally, larger diameter or heavy wall thickness stainless steel pipe use percentage, small diameter or thin wall thickness stainless steel tube use absolute value.

Standard	Manufacturing Process & Type	Outer Diameter Tolerance		Wall Thickness Tolerance	Others
Standard	Manufacturing Process & Type	OD (Mm)	Class	Wall Thickness Tolerance	Others
EN10216-5	Hot Finished Seamless Tube	219.1-610	D1	+22.5%T，-15%T	T/D≤0.05
				T1	T/D≤0.09
				T2	T/D>0.09
		30-219.1	D2	T1
		30-219.1	D2	T2
	Cold Finished Seamless Tubes	≤219.1	D3	T3
	Cold Finished Seamless Tubes	≤219.1	D4	T4	Agreement
EN10297-2	Hot Finished Seamless Tube		D1	T1
	Hot Finished Seamless Tube		D2	T2	Agreement
	Cold Finished Seamless Tubes		D3	T3
	Cold Finished Seamless Tubes		D4	T4	Agreement
EN10217-7	Welded Tubes	>168.3	D2	T3
		≤168.3	D3	T3
		≤168.3	D4	T3	Agreement
EN10296-2	Welded Tubes	>168.3	D2	T3
		≤168.3	D3	T3
		≤114.3	D4	T3	Agreement
EN10312	Welded Tubes	Series 1	D4	T3	T=0.6-2 Mm
EN10312	Welded Tubes	Series 2	D3 – D4	T3 – T4	T=1-3 Mm

From D1 to D4 class for outer diameter, and T1 to T4 for wall thickness tolerance comply to DIN EN ISO 1127 standard, stainless steel tubes – Dimensions, tolerances and conventional masses per unit length.

Outside Diameter		Wall Thickness
Class	Tolerance	Class	Tolerance
D1	±1.5%, Or ±0.75 Mm Min.	T1	±15%, Or ±0.6 Mm Min.
D2	±1.0%, Or ±0.5 Mm Min.	T2	±12.5%, Or ±0.4 Mm Min.
D3	±0.75%, Or. ±0.3 Mm Min.	T3	±10%, Or ±0.2 Mm Min.
D4	±0.50%, Or ±0.1 Mm Min.	T4	±7.5%, Or ±0.15 Mm Min.
		T5	+/- 5.0 %, Or +/- 0.10 Mm Min.

The tolerances on outside diameter and thickness from above table, greater value shall be selected.

EN 10312 has specific values in table series 1 and series 2.

America Standard

America standard has two standard rules to specify outside diameter and thickness, ASTM A999 / A999M and A1016 / A1016M.

ASTM A999	ASTM A1016
ASTM A312 / A12M A358 / A358M A376 / A376M A409 / A409M A778 A790 / A790M A813 / A813M A814 / A814M A928 / A928M	A213 / A213M A249 / A249M A268 / A268M A269 A270 A688 / A688M A789 / A789M A803 / A803M

But A511 for seamless stainless steel mechanical tubing and A554 welded stainless steel mechanical tubing not conform to above standards, they have separate outside diameter and thickness tolerances.

Standard	Manufacturing & delivery condition	Outside Diameter OD / mm	OD tolerance mm	Thickness T / mm	T tolerance mm
Standard	Manufacturing & delivery condition	Outside Diameter OD / mm	OD tolerance mm	Thickness T / mm	Minimum	Average
ASTM A1016 A1016M	Hot drawn seamless tubes	<=100	+0.4, -0.8	<=2.4	+0.4t, 0
		100 – 200	+0.4, -1.2	2.4 – 3.8	+0.35t, 0
		200 – 225	+0.4, -1.6	3.8 – 4.6	+0.33t, 0
				>=4.6	+0.28t, 0
	Cold drawn seamless tubes	<25	+0.1, -0.11		+0.20t, 0	+/-0.10t
		25 – 40	+0.1, -0.11		+0.20t, 0	+/-0.10t
		40 – 50	+/-0.2		+0.22t, 0	+/-0.10t
		50 – 65	+/-0.25
		65 – 75	+/-0.3
		75 – 100	+/-0.38
		100 – 200	+/-0.38, -0.04
		200 – 250	+/-0.38, -1.14
	Welded tubes	40 – 50	+/-0.2		+0.18t, 0	+/-0.10t
		50 – 65	+/-0.25
		65 – 75	+/-0.3
		75 – 100	+/-0.38
		100 – 200	+/-0.38, -0.04
		200 – 250	+/-0.38, -1.14
ASTM A999 / M	Seamless tubes and welded tubes	<48.3	+0.4, -0.8			-0.125t
ASTM A312 / M	Seamless tubes and welded tubes	48.3-114.3	+/-0.8	OD=10.3-73		+0.20 t, -125t
		168.3-219.1	+1.6, -0.8	t/OD<=5% OD=88.9-457.2		+0.225 t, -125t
		219.1-457.2	+2.4, -0.8	t/OD>5% OD=88.9-457.2		+0.15 t, -125t
	Welded tubes	508-660	+3.2, -0.8	OD>=508		+0.175 t，-0.125 t
	Welded tubes	711-864	+4.0, -0.8	t/OD<=5%, OD>=508		+0.225 t，-0.125 t
	Seamless tubes	914-1209	+4.8, -0.8	t/OD>5%, OD>=508		+0.15 t, -125t
ASTM A409 / M	Welded tubes		+/-0.2%	T<4.8
ASTM A409 / M	Welded tubes		+/-0.4%	t>=4.8
ASTM A358 / M	Welded tubes		+/-0.50%
ASTM A511	Seamless tubing	<=12.7	+/-0.1			+/-0.15t
		12.7-38.1	+/-0.2			+/-0.10t
		38.1-88.9	+/-0.3
		88.9-139.7	+/-0.4
		139.7-203.1	+/-0.8
		203.1-220	+/-1.1
		220-325	+/-1.6

American standard outside diameter tolerance mainly used to represent the absolute value, over and below tolerances are often asymmetric, SS tube and pipe in American standard average tolerance can reach even higher than D4 class in EN ISO 1127 standard.

Wall thickness tolerance should be +/-10%t or better, and average thickness tolerance should be ( +/-20 – 22%t, 0 ), pipeline pipe has a larger tolerance, hot finished seamless pipe largest.

China Standards

China has more quantity standards compared to European standards, but less than american standards, SS tube and pipe standards are similar with EU standards in system, and absorb favorable experience in USA specifications.

Specification	Manufacturing	O.D(Mm)	O.D Tolerance	W.T(Mm)	W.T Tolerance
GB13296	Cold Rolled Seamless Pipe	6-30	±0.15/-0.2	1-3	+20%	-0%
		＞30-50	±0.3	＞3	+22%	-0%
		＞50	±0.75%	Also Average Wall
GB/T14976	Cold Rolled Seamless Tube	6-10	±0.15	1-3	+12.5%	-12.5%
		10-30	±0.2	＞3	+12.5%	-10%
		30-50	±0.3	Average Wall, +22%
		＞50	±0.8%	Average Wall, +22%

Standard Comparison

Stainless steel tube & pipe wall thickness tolerance are the same as the general accuracy of American ASTM / ASME and EU standards, but slightly lower than the high requirements of the EU standards.

Stainless steel tube & pipe outer diameter tolerances are mostly lower than American standards, and approaching the EU standards. it is more reasonable that the American standard specify the OD tolerance is tight, compared to thickness tolerance.

China GB standards and EU standard have no weight tolerance specified, seamless tube & pipe in GB standard delivery goods as actual weight or theoretical weight, welded tube & pipe as theoretical weight or actual weight.

Out Of Roundness

Out of roundness, sometimes referred to as ovality is tube or pipe on the same cross-section of the outer diameter, roundness or ovality is difference between the maximum and minimum dimensions of outside diameter, is carefully measured the high and low points at any one section of the tube or pipe.

Eccentricity

Concentricity or eccentricity refers to tube & pipe wall thickness variations, if need a high precision in tube tolerance, or fit into other tube or parts, which need a good concentricity.

Concentricity be contained wall thickness tolerance specified in EU standard, and just specified in ASTM A1016/M OD≥50 mm and t≥5.6 mm thick wall stainless steel tube the same cross section thickness varieties.

For seamless tube,

WTmax – WTmin ≤ ±10% (WTmax + WTmin) / 2

For welded tube,

WTmax – WTmin ≤ 5% (WTmax + WTmin) / 2

Straightness

Standard pipes and tubes are supplied straightened to the eye: for special applications the permissible deviation from the straight line may be agreed between purchaser and tube manufacturer; the maximum permissible deviation from the straight line related to the length of measurement L is to be indicated, e.g. 1mm/1000mm.

For example:

OD Mm ≤	OD Inches ≤	Wall	Straightness Commercial	FT Achievable Mm
15.9	0.625	All Sizes	1 In 600	1 In 2000
25.4	1.00	2% Of OD Or Heavier	1 In 600	1 In 1500
25.4	1.00	Less Than 2% Of OD	1 In 400	1 In 1000

Length of stainless steel pipe and tube

Delivery length is also called the length required by the user or the length of the order. The standard has the following regulations on delivery length:

A. Normal length / Random Length (also called non-fixed-length length): Any stainless steel tube whose length is within the length range specified by the standard and has no fixed length requirement is called normal length. For example, the structural stainless steel pipe standard stipulates: hot-rolled (extruded, expanded) steel pipe 3000mm - 12000mm; cold drawn (rolled) steel pipe 2000mm - 10500mm.

B. Fixed Length: The fixed-length should be within the usual length range, which is a certain fixed-length dimension required in the contract. However, it is impossible to cut out the absolute fixed-length length in actual operation, so the standard stipulates the allowable positive deviation value for the fixed-length length.

Take the structural stainless steel pipe standard as:

The yield rate of production of fixed-length pipes is much lower than that of normal-length pipes, and it is reasonable for manufacturers to request price increases. The rate of price increase varies from company to company. Generally, the price increase is about 10% on the basis of the base price.

C. Length of double ruler: The length of the double ruler should be within the usual length. The contract should indicate the length of the single ruler and the multiples of the total length (for example, 3000mm×3, which is 3 multiples of 3000mm, and the total length is 9000mm). In actual operation, the allowable positive deviation of 20mm should be added to the total length, plus a margin for the incision of each single ruler length. Take the structural pipe as an example, the allowance for cutting is stipulated: 5-10mm for outer diameter ≤159mm; 10-15mm for outer diameter >159mm.

If there is no double-length deviation and cutting allowance in the standard, it should be negotiated by the supplier and the buyer and indicated in the contract. The double-length scale is the same as the fixed-length length, which will bring about a substantial reduction in the yield rate of the manufacturer. Therefore, it is reasonable for the manufacturer to raise the price, and the price increase is basically the same as the fixed-length length.

D. Range length: The range length of the stainless steel pipe is within the usual length range. When the user requires a fixed range length, it must be indicated in the contract.

For example: Usually the length is 3000-12000mm, and the range cut-to-length length is 6000-8000mm or 8000-10000mm.

It can be seen that the range length is looser than the fixed-length and double-length length, but it is much stricter than the usual length, which will also reduce the yield of production enterprises. Therefore, it is reasonable for the manufacturer to raise the price, and the price increase is generally about 4% above the base price.

Stainless Steel Density

Stainless steel density refers to substance mass per unit volume, it is one of typical property of stainless steel, commonly, density of stainless steel range from 7600 kg/m3 to 8000 kg/m3.

Stainless steel is a wide used material, containing at least 10.5% of Chromium, and other elements added to form stainless steel structure, these elements have Carbon, Silicon, Manganese, Phosphorus, Sulfur, Nickel, Molybdenum, Titanium and Copper, it is noted as high strength and excellent corrosion resistance.

Densities change depending on these alloy elements changing, different alloy content have different density value, even it is the same grade, it is difficult to calculate accurate density values, theoretic density value is given below for reference.

The following is the comparison of several commonly used stainless steel density, data may not be completely accurate, only for reference.

Material 201, 202, 301, 302, 304, 304L, 305, 321
Density 7.93 7.93 7.93 7.93 7.93 7.93 7.93 7.93

Stainless Steel Density Table Chart

Grade	Density ( G / Cm3 )	Density ( Kg / M3 )
201 202 301 302 303 304 304L 304LN 305 321	7.93	7930
309S 310S 316 316L 316Ti 316LN 317 317L 347	7.98	7980
904L	7.98	7980
2205 S31803	7.80	7800
S32750	7.85	7850
403 410 410S 416 431	7.75	7750
440A	7.74	7740
440C	7.62	7620
420	7.73	7730
439 430 430F	7.70	7700
434	7.74	7740
444	7.75	7750
405	7.72	7720

*These densities given at standard conditions for temperature and pressure condition.

304 And 316 Stainless Steel Densities

304 and 316 are the most used stainless steel grades, their densities are not the same, this decide by chemical composition and content, stainless steel 304 density is 7930 kg / m3, 316 density is 7980 kg / m3, so when calculating stainless steel weight, it is different between 304 and 316 stainless steel.

Stainless Steel Density Conversion, Kg/M3, G/Cm3 And Lbs/In3
Density of stainless steel calculated by dividing the mass by the volume, usually measured in g/cm3, kg/m3, and lbs/in3, each unit can be converted to other units.

Conversion: 1 kg/m3 = 0.001 g/cm3 = 1000 g/m3 = 0.000036127292 lbs/in3.

Density Relations With Temperature And Pressure

Densities of stainless steel vary by changing either the temperature or the pressure, in general, increasing the temperature decreases the density, increasing the pressure always increases the density.

Difference Between Seamless And Welded Tube & Pipe

Seamless and welded are mainly two types stainless steel tube & stainless steel pipe, there is a debate whether seamless is better than welded for a long time.

Although with improved metallurgy and welding processes in welded tubes, the arguments typically focus on structural integrity and corrosion resistance in weld area.

Obviously, seamless and welded tubes & pipes difference is manufacturing process.

There are some cases where paying extra for a different, higher-performing alloy is necessary.

Welded Tube Manufacturing Process

Depending on the outer dimension, wall thickness and final application, there are different ways of manufacturing welded tubes and pipes, and different manufacturing method.

Strip Welded Tubes & Pipes

Welded tube start from stainless steel strip and coil that is passed through grooved rollers till the shape is formed and the free edges are properly shaped for welding, cold forming is performed step by step from flat strip into a round profile, the edges are welded together as they approach the welding rolls.

Typical welding method for strip welded tubes is traditionally autogenous tungsten inert gas (TIG), TIG welding method have some advantages that can effectively protect weld seam.

After welding outside and inside grinding of the weld seam, solution annealing or stress relieving may be necessary by application requirements.

TIG Welding Stainless Steel Tubing

Coil
Inspection and analysis
Slitting
Auto-welding
Seam-grinding
Solution treatment
Cut to length
Straightening

Picking
End-facing
Eddy current test
Hydrostatic test
Final inspection
Marking
Packing
Shipping

Today, most of the modern welding lines are equipped with inline induction annealing, then straitening and calibration to control dimension of tube & pipe, cut to standard or special lengths, de-burred, NPD & DT testing and inspection should be carried out as standard or requirement.

Heavy Wall Tubes & Pipes

When large outside diameter or heavy wall or both welded tubes & pipes required, there is a different welding method and process, for large diameter and heavy wall pipes, EFW, ERW and other welding methods can be used.

Starting from stainless steel plate or sheet, the forming is done in a roller bending machine or in a hydraulic press, then some steps are same with strip welded tubes.

Plate
Inspection
Plasma-cutting
Edging
Bending
Seam cleaning
Forming
Auto- welding
Degreasing

Anneaspanng
Roundness caspanbrating
End-facing
Eddy current test
Hydrostatic test
Final inspection
Marking
Packing
Shipping

For testing and inspection, large diameter sizes, radiography test (RT) and hydrostatic test (HT) are often required.

For large diameter welded pipes, double welding method can be accepted.

Seamless Tube Manufacturing Process

Seamless tubes are generally made in complex steps starting with the drilled hollows from billets, by cold drawing and cold rolling manufacturing process with cold drawing & cold rolling machines.

Stainless steel pipe polishing

Stainless steel pipe doesn't look all shiny and new right off the welding line. In fact, it looks burnt and kind of charred. Polishing it will give it that mirror finish (or satin silver finish) that makes it such an attractive accessory. Stainless steel pipe polishing is an important process for manufactures and architectural applications. Polishing stainless steel pipes creates a uniform and consistent surface finish–vital for tank manufactures and OEMs supplying products to the chemical and pharmaceutical industries.

Beveling

Beveling Stainless Steel pipes contain one end angled, so that it mates with a complementary pipe end. Pipes can be beveled for certain applications in order to make welding of stainless steel pipes easier, which saves weld prep time and money compared to hand cutting.

Heat treating & Annealing

Stainless steel pipe annealing is an important production process and the heat treatment is mostly carried out under controlled conditions to avoid carburization, decarburization and scaling on the metal surface. Stainless steel pipe annealing is a solution treatment employed for recrystallizing the work-hardened austenitic stainless steels and drawing chromium carbides. In addition, stainless steel pipe annealing removes stresses occurred during sold-working, and homogenizes dendritic stainless steel welds.

UT Testing

Ultrasonic Testing (UT) utilizes sound energy at high frequencies to provide examinations and measurements of the stainless steel product. This aids in flaw detection/evaluation, dimensional measurements, etc.

Stainless pipe length cutting

We offer Dynamic Waterjet Cutting， Plasma Cutting， Laser Cutting as part of our full line of stainless steel processing services

Stainless steel tube bending

We bend pipe and tube to your specification using our high precision machinery. 18 years of expertise in producing high quality bends with tight bend radius. We can bend tube and pipe at most diameters from 25 mm to 76 mm diameter in a wide range of materials including mild steel, stainless steel and others up to 6-meter lengths.

Range of application

Stainless steel pipe (tube) has excellent characteristics of corrosion resistance and smooth finishing. Stainless steel pipe (tube) is commonly used in demanding equipment like automobiles, food processing, water treatment facilities, oil and gas processing, refinery and petrochemicals, breweries and energy industries.

Considering the importance of outside and inside surface of stainless steel tubes for fluid power industry, Our mills are providing tubes that are free from scale, rust, seams, laps.

The stainless steel tubing that is supplied by SunnySteel can used in a variety of industries, including:

Machinery Parts
Pharmaceutical
Biotechnology
Automotive
Oil and Gas
Marine

Food and Beverage Processing
Construction
Automotive industries
Food processing
Water treatment facilities
Breweries and energy industries

The main requirement for stainless steels is that they should be corrosion resistant for a specified application or environment. The selection of a particular "type" and "grade" of stainless steel must initially meet the corrosion resistance requirements.

Additional mechanical or physical properties may also need to be considered to achieve the overall service performance requirements.

Tech & Grade for Stainless steel:

Stainless steel is one of the more standardized materials in the building and engineering industries.