site logo

Stainless steel tube

Stainless steel tube

Time:2022-04-07 Source:Wuxi Jianuo Special Steel Co.

Stainless steel pipe is a kind of hollow long round steel, mainly widely used in petroleum, chemical, medical, food, light industry, mechanical instrumentation and other industrial transmission pipeline and mechanical structure parts. In addition, when the bending and torsion strength is the same, the weight is lighter, so it is also widely used in the manufacture of mechanical parts and engineering structures. Also commonly used for furniture and kitchenware.


1 Detailed introduction


Brinell hardness

Rockwell hardness ▪ Rockwell hardness

Vickers hardness ▪ Vickers hardness

Hardness testing ▪ Hardness testing

2 Development

3 Trade

4 Properties

5 Processes

6 Tensile Strength

7 Flexural strength

8 Classification

Production method

Section shape ▪ Section shape

Tube end shape

▪ Application classification


9 Stainless steel industry

10 304 steel rust phenomenon causes

11 Application prospects

▪ Promotion

▪ Domestic prospect is good

12 Connection method

13 Marking method

▪ Representation method

▪ Numbering rules

▪ Labeling method

▪ Standard classification

14 New Products

▪ 200 series

two-way type ▪ two-way type

▪ Boiler type

15 Specification Sheet

▪ Duplex stainless steel

16 Weight calculation

17 Stainless steel tube execution standards

18 Application requirements

Automotive industry

petrochemical industry including fertilizer industry

Fluid transportation such as water and gas

Equipment manufacturing and maintenance

19 Material classification



Stainless steel pipe is generally used Brinell, Rockwell, Vickers three hardness indicators to measure its hardness.

Brinell hardness

In the stainless steel tube standards, Brinell hardness is the most widely used, often to indentation diameter to indicate the hardness of the material, both intuitive and convenient. But for harder or thinner steel tubes of steel does not apply.

Rockwell hardness

Stainless steel pipe Rockwell hardness test is the same as Brinell hardness test, are indentation test method. The difference is that it measures the depth of the indentation. Rockwell hardness test is a widely used method, in which HRC in the steel pipe standards used second only to Brinell hardness HB. Rockwell hardness can be applied to determine the metal material from very soft to very hard, it makes up for the Brinell method is not, easier than the Brinell method, can be read directly from the dial of the hardness machine hardness value. However, due to its small indentation, the hardness value is not as accurate as the Brinell method.

Vickers hardness

Stainless steel pipe Vickers hardness test is also an indentation test method, can be used to determine the hardness of very thin metal materials and surface layers. It has the main advantages of Brinell, Rockwell method, while overcoming their basic shortcomings, but not as easy as Rockwell method, Vickers method is rarely used in the steel pipe standards.

Hardness testing

Stainless steel pipe inside diameter of 6.0mm or more, wall thickness of 13mm below the annealed stainless steel pipe, you can use W-B75 type Wechsler hardness tester, it is very fast and easy to test, suitable for stainless steel pipe to do a rapid non-destructive qualified inspection. Stainless steel pipe inner diameter greater than 30mm, wall thickness greater than 1.2mm stainless steel pipe, using Rockwell hardness tester, test HRB, HRC hardness. Stainless steel pipe inner diameter greater than 30mm, wall thickness less than 1.2mm stainless steel pipe, using the surface Rockwell hardness tester, test HRT or HRN hardness. Inner diameter of stainless steel pipe less than 0mm, more than 4.8mm stainless steel pipe, the use of pipe special Rockwell hardness tester, test HR15T hardness. When the inner diameter of the stainless steel tube is greater than 26mm, you can also use Rockwell or surface Rockwell hardness tester to test the hardness of the inner wall of the tube.

Development Editor Podcast

Any steel that is open at both ends and has a hollow section, and whose length is greater than the perimeter of the section, can be called steel pipe. When the length compared to the perimeter of the section is small, it can be called a pipe section or pipe fitting, and they all fall under the category of pipe products.

For more than sixty years, architects have been choosing stainless steel to construct cost-effective permanent buildings. Many existing buildings amply illustrate the validity of this choice. Some are very ornamental, such as the Chrysler Building in New York City. But in many other applications, stainless steel plays a less dramatic role, but in the aesthetic and performance aspects of the building plays an important role. For example, because stainless steel is more wear-resistant and indentation-resistant than other metal materials of the same thickness, so it is the material of choice for designers when building sidewalks in places with high population movement.

Stainless steel has been used for more than 70 years as a structural material for the construction of new buildings and for the restoration of historic monuments. In the early days, designs were calculated according to basic principles. Today, design codes, such as the American Society of Civil Engineers standard ANSI/ASCE-8-90 “Code of Practice for the Design of Cold-Formed Stainless Steel Structural Members” and the “Structural Stainless Steel Design Manual” published by NiDI in conjunction with Euro Inox have simplified the design of structural members for buildings with long life and good integrity.

Trade situation Editorial Podcast

Stainless steel exports are an important part of China’s export economy, which has an important role in driving China’s economic growth, but, from the current situation of China’s stainless steel foreign trade, China’s stainless steel exports have encountered greater resistance.

Since last year, foreign frequent news of China’s stainless steel casting products “double reverse” news, which has a great impact on China’s stainless steel casting industry, exports are a large part of the development of China’s stainless steel industry, in the development of its industry has a huge market share, in the face of the economic downturn, the slowdown in the development of the situation In the face of economic downturn and slowdown, the development of China’s stainless steel industry should continue to improve product quality, better development of overseas trade and to deal with the suppression of trade protectionism, the combination of products and environmental protection, energy resources, human environment, improve the competitiveness of stainless steel products, only in this way can we achieve an invincible position in foreign trade.

Properties Editor Podcast

Surface resistance less than 1000 megawatts; wear protection; stretchable; excellent chemical resistance; good alkali metal and acid resistance; toughness; flame retardant.


The production process of seamless stainless steel pipe.

a. Round steel preparation.

b. Heating.

c. Hot rolling and piercing.

d. Cutting head

e. Pickling.

f. Grinding

g. Lubrication

h. Cold rolling process

i. Degreasing

j. Solution heat treatment.

k. Straightening

l. Cutting


n. Finished product inspection.

Tensile strength


Strength refers to the ability of a metal to resist plastic deformation and fracture under the action of an external force

Tensile strength

When a metal specimen is stretched, the ratio of the maximum load to the original cross-sectional area of the specimen before breaking is called tensile strength

Bending strength

Specimen is located in the middle of the two support of the concentrated load, so that the fracture, the maximum positive pressure on the fracture section

P – the maximum concentrated load on the specimen (N)

L – the span between the two support points (mm)

d – the outer diameter of the cross-section of the circular specimen (mm)

b – the width of the rectangular section specimen (mm)

h – the width of the rectangular section specimen (mm)


Stainless steel pipe is divided into ordinary carbon steel pipe, high quality carbon structural steel pipe, alloy structural pipe, alloy steel pipe, bearing steel pipe, stainless steel pipe, as well as to save precious metals and meet the special requirements of bimetallic composite pipe, plating and coating pipe. Stainless steel tube of a wide variety of different uses, its technical requirements vary, the production method is also different. The current production of steel pipe outside diameter range 0.1-4500mm, wall thickness range 0.01 ~ 250mm. to distinguish their characteristics, usually according to the following method of classification of steel pipe.

Production method

Stainless steel pipe according to the production method is divided into seamless and welded pipe two categories, seamless steel pipe can be divided into hot-rolled pipe, cold-rolled pipe, cold-drawn pipe and extruded pipe, cold-drawn, cold-rolled is the secondary processing of steel pipe; welded pipe is divided into straight seam welded pipe and spiral welded pipe, etc..

Section shape

Stainless steel pipe according to the cross-sectional shape can be divided into round and shaped pipe. Shaped tubes are rectangular tubes, diamond-shaped tubes, oval tubes, hexagonal tubes, eight square tubes and a variety of cross-sectional asymmetric tubes. Shaped tubes are widely used in various structural parts, tools and mechanical parts. Compared with round tubes, shaped tubes generally have a larger moment of inertia and cross-sectional modulus, have greater resistance to bending and torsion, can greatly reduce the weight of the structure, saving steel.

Stainless steel tube according to the shape of the longitudinal section can be divided into equal section tube and variable section tube. Variable section tube has a tapered tube, stepped tube and periodic section tube.

Tube end shape

Stainless steel tube according to the end state can be divided into light tube and threaded tube (with threaded steel tube). The threaded pipe can be divided into ordinary threaded pipe (water, gas and other low pressure pipe, using ordinary cylindrical or tapered pipe thread connection) and special threaded pipe (oil, geological drilling pipe, for important threaded pipe, using special threaded connection), for some special pipe, in order to compensate for the impact of the thread on the strength of the pipe end, usually before the threaded pipe end thickening (inside thickening, outside thickening or inside and outside thickening).

Application classification

According to the application, it can be divided into oil well pipe (casing, oil pipe and drill pipe, etc.), pipeline pipe, boiler pipe, mechanical structure pipe, hydraulic pillar pipe, gas cylinder pipe, geological pipe, chemical pipe (high-pressure fertilizer pipe, petroleum cracking pipe) and marine pipe, etc.


Stainless steel welded pipe production process.

Raw material – Slitting – Welding pipe – Repairing end – Polishing – Inspection (printing) – Packaging – Shipping (warehousing) (decorative welded pipe).

Raw material – Slitting – Welding pipe – Heat treatment – Straightening – Straightening – End trimming – Pickling – Hydrotesting – Inspection (printing) – Packaging – Shipping (warehousing) (Welded pipes for industrial piping).

Stainless steel industry

Stainless steel industry is a new industry, originated in the early 1980s, after 20 years of exploration and exploration, in the domestic market has become quite well-known and a certain influence.

Current production enterprises amount to more than 130, with good momentum of development and expansion. The whole industry has 38 sets of piercing equipment. More than 500 sets of cold rolling and cold drawing equipment, 6 smelting equipment, all of which are refined outside the furnace, and other equipment is relatively complete. The production capacity and scale of enterprises are constantly expanding and enhancing. 2001 year, there are 5 enterprises with output value over 100 million yuan, and more than 10 enterprises are rated as star enterprises in the city and district. In order to ensure the quality of products, water pressure, eddy current and ultrasonic flaw detection, direct reading spectrometer and other analysis and testing equipment are constantly increasing and improving. 2001 by the higher technical supervision department sample testing, the pass rate reached more than 80%. With various types of senior and middle-level titles of technical and management personnel more than 300 people, is the enterprise gradually on the standardized production, management track. Wenzhou stainless steel industry is mainly the production of stainless steel pipe and stainless steel bar, varieties, specifications, models have reached more than 400 kinds. 2001 stainless steel sales reached 1.715 billion yuan, production reached 106,000 tons. Stainless steel bar 222 million yuan, production of 2,110,000 tons, the state taxes paid to more than 100 million yuan. Steel pipe exports also increased year by year, 5,000T in 2001, is expected to export 8,000 ~ 10,000T this year, there are 10 or so enterprises to obtain self-management import and export rights. Stainless steel pipe exported to Southeast Asia, the European Union dozens of countries and regions, by foreign businessmen and users of the appreciation.

Stainless steel pipe industry in the original is a blank, rapid development, the scale is expanding, but the production capacity there is still a certain gap, still can not meet the needs of the domestic market. Stainless steel industry in the future development of ideas and specific practices are.

⒈ to improve product output as the center, strengthen the internal management of enterprises, improve the scale of enterprises, grade as the goal, to further improve the visibility of stainless steel tubes and enterprises, encourage the development of enterprises to the group, strengthen the introduction and training of technical personnel, management personnel, strengthen the construction of production equipment to ensure and improve product quality.

Peal towards the road of brand development, the number of stainless steel industry and the credit of entrepreneurs, shaping China’s brand awareness.

Χ Establish a stainless steel pipe production park, gathering stainless steel production enterprises, so that the scale, upscale, create a leader, create a brand name, the formation of a group production; through mergers, dependencies, equity participation, joint, etc., to achieve the Zhejiang Province Economic and Trade Department’s “focus on the development” of the planning goals.

Singing the professional market of stainless steel. The stainless steel industry is developing rapidly, but without a professional market of a certain scale, it cannot attract customers from all over the world, so the production enterprises can only operate in various parts of the country, which increases the cost and hinders the development of enterprises. If built a professional market, set production, sales services in one, will make the production of enterprises really based on the back of the country, to the country, out of the country.

304 steel rust phenomenon causes

Chlorine ions are widely present, such as salt, sweat traces, seawater, sea breeze, soil, etc.. Stainless steel in the presence of chloride ions in the environment, corrosion is very fast, even more than ordinary low carbon steel, chloride ions and alloy elements in the formation of Fe complexes, Fe positive potential will be reduced, followed by oxidizing agents to take away electrons and be oxidized .

So there are requirements for the use of stainless steel environment, and the need to frequently wipe, remove dust, keep clean and dry.

316 and 317 stainless steel is a molybdenum-containing stainless steel species. 317 stainless steel has a slightly higher molybdenum content than 316 stainless steel. Due to the molybdenum content in 316 stainless steel, the overall performance of this steel grade is better than 310 and 304 stainless steel. 316 stainless steel has a wide range of applications under high temperature conditions when the concentration of sulfuric acid is below 15% and above 85%. 316 stainless steel also has good resistance to chloride attack, so it is usually used in marine environments.

Application Prospects

Stainless Steel Tubes

Stainless steel pipe is an economic section steel, is an important product in the steel industry, can be widely used in life decoration and industry, many people on the market for the production of stairs handrails, window guards, railings, furniture, etc.. Commonly available are 201 and 304 two kinds of materials.

Accounting for about 8% a 16% of all steel, it is used in an extremely wide range of applications in the national economy. Because of the steel pipe has a hollow section, and therefore the most suitable for liquid, gas and solid transport pipeline; at the same time with the same weight of round steel, steel pipe section coefficient, bending and torsional strength, so also become a variety of machinery and building structure on the important material. Structures and components made of stainless steel tubes have a larger cross-sectional modulus than solid parts under equal weight. Therefore, the stainless steel tube itself is a metal-saving economic section steel, it is an important part of efficient steel, especially in the oil drilling, smelting and transmission industries are in greater demand, followed by geological drilling, chemical industry, construction industry, machinery industry, aircraft and automobile manufacturing, as well as boilers, medical equipment, furniture and bicycle manufacturing also need a large number of various steel tubes. With the development of new technologies such as atomic energy, rockets, missiles and space industry, stainless steel pipe in the defense industry, science and technology and economic construction has become increasingly important.

Stainless steel pipe is safe, reliable, sanitary and environmentally friendly, economical, thin-walled pipes and new reliable, simple and convenient connection methods are developed successfully, so that it has more irreplaceable advantages of other pipes, the application of engineering will be more and more, the use of more and more popular, the prospects are good.

As stainless steel has many of the ideal properties required for building materials, it can be said to be unique in the metal, and its development continues. To make stainless steel perform better in traditional applications, improvements have been made to the existing types, and new stainless steels are being developed to meet the stringent requirements of advanced architectural applications. Due to increasing production efficiency and improving quality, stainless steel has become one of the most cost effective materials chosen by architects.

Stainless steel combines performance, appearance and use characteristics, so stainless steel will remain one of the world’s best building materials.

With the implementation of China’s reform and opening-up policy, the national economy has gained rapid growth, urban residential, public buildings and tourism facilities are built in large numbers, the hot water supply and domestic water supply has put forward new requirements. In particular, the water quality issue has become more and more important and the requirements have been increasing. Galvanized steel pipe, a common pipe because of its easy corrosive, under the influence of relevant national policies, will gradually withdraw from the historical stage, plastic pipe, composite pipe and copper pipe into the common pipe of the piping system. But in many cases, stainless steel pipe is more superior, especially the wall thickness of only 0.6 ~ 1.2mm thin-walled stainless steel pipe in high-quality drinking water systems, hot water systems and water supply systems that put safety and health first, with safe and reliable, health and environmental protection, economic and other characteristics. Has been proven by domestic and foreign engineering practice is the best comprehensive performance of the water supply system, new, energy-saving and environmentally friendly pipe, is also a very competitive water supply pipe material, will play an incomparable role in improving water quality, improve people’s living standards.

In the building water supply system, as galvanized steel pipe has ended a hundred years of glorious history, a variety of new plastic pipes and composite pipes have been rapidly developed, but a variety of pipes still have some shortcomings to varying degrees, far from fully adapt to the needs of the water supply system and the country’s requirements for drinking water and related water quality. Therefore, the relevant experts predict that the building water supply pipe material will eventually return to the era of metal pipe. According to foreign application experience, in the metal pipe identified thin-walled stainless steel pipe as one of the best overall performance of the pipe.


Thin-walled stainless steel pipe, domestic production and use in the late 1990s, is the emerging new family in the field of pipe, has been used in large quantities in the building water supply and direct drinking water pipeline.

Thin-walled stainless steel pipe durable, has been recognized by the engineering community, and the relevant parties are reducing the wall thickness, reduce prices to facilitate further promotion. Especially small diameter stainless steel pipe, the price is not high, so the supporting connection method, the reliability of the fittings and price is the main factor in determining its development. Domestic developers in Sichuan, Guangdong, Zhejiang, Jiangsu and other places have developed their own connection technology and fittings, is a very promising pipe development. The Ministry of Construction and related departments also attach great importance to this new pipe, according to the Chinese Technology Market Management Promotion Center, National Science and Technology City word [2001] No. 71 document, on the promotion and application of “high diameter wall ratio high-precision stainless steel water pipe and supporting fittings and special technology” notice was informed that the thin-walled stainless steel pipe technology and products The promotion and application of this technology and products to improve the grade of China’s modern buildings, improve and protect water quality are of great significance.

At the same time, the Ministry of Construction attaches great importance to the promotion and application of thin-walled stainless steel pipes. The industry standard of “thin-walled stainless steel water pipe” was released in 2001. Related pipeline engineering technical regulations and installation atlas, the Ministry of Construction has issued a document, is responsible for the preparation of Tongji University. Currently, Sichuan, Guangdong, Zhejiang, Jiangsu and other places have professional manufacturers of thin-walled stainless steel pipe production, the product has tended to mature, thus, the time has come to promote the application.

Domestic prospects are good

① building water supply pipeline demand

According to the “building business” Ninth Five-Year Plan and 2010 Visionary Goals Outline” estimates, 2001 to 2010, the annual demand for pipes for 50 ~ 600,000 km, of which the demand for hot and cold water pipes in residential buildings for 400,000 km. grade, is of great significance.

② Pipeline direct drinking water is developing rapidly

With the development of the national economy, pipeline direct drinking water in the domestic cities of Beijing, Shenzhen, Shanghai, Chongqing and other cities are developing rapidly, economically developed medium-sized cities are also actively planning to catch up straight. In the direct drinking water, stainless steel pipe system is undoubtedly second to none. The current domestic upscale hotels, public places have been configured or in the configuration of direct drinking water pipeline.

③ domestic alternative to imports has a bright future

In order to promote stainless steel pipe, China since the 1990s from the reduction of wall thickness, reduce costs, to solve the “high diameter wall than high-precision” thin-walled stainless steel pipe technology, so that the application of stainless steel pipe to promote the rapid development. A pipeline to be able to fully promote the application, less localization. When, the domestic manufacturers have a part of the production and further development of thin-walled stainless steel pipe and fittings capabilities.


Stainless steel pipe is connected in a variety of ways, common types of pipe fittings are compression, compression, live connection, propulsion, push threaded, socket welding, live flange connection, welding and welding combined with the traditional connection of the derivative series of connections. The scope of application of these connections varies according to their principles, but most of them are easy to install, solid and reliable. Most of the sealing ring or gasket materials used for the connection are silicon rubber, nitrile rubber and EPDM rubber, which meet the requirements of national standards and eliminate the worries of users.

Steps of snap connection

1、Break the pipe: cut the pipe according to the required length, when breaking the pipe, do not use too much force to prevent the pipe from losing round.

2、Remove burr: After cutting off the pipe, the burr should be removed cleanly to avoid cutting the seal.

3、Marking line: In order to make the steel pipe completely inserted into the pipe socket, the length of insertion must be marked at the end of the pipe to draw a line.

4, assembly: the seal should be correctly installed in the U-groove of the pipe fittings, the pipe into the pipe fittings socket, waiting for crimping.

5, crimping: crimping, the raised part of the pipe fittings placed in the mold concave groove, the jaws and tube axis to maintain vertical.

6, check: crimping is complete, use special gauges to check the size of the crimp.

Marking Method

Indication method

① Use the international chemical element symbols and the symbols of the country to indicate the chemical composition, using Arabic letters to indicate the content of the composition.

Such as: China, Russia 12CrNi3A

② with a fixed number of digits to indicate the steel series or numbers; such as: the United States, Japan, 300 series, 400 series, 200 series.

③ with Latin letters and order to form a serial number, only to indicate the use.

Numbering rules

① the use of elemental symbols.

② Hanyu Pinyin, flat-furnace steel: P; boiling steel: F; sedimentation steel: B; Class A steel: A; T8: special 8; GCr15: ball.

◆Harmonized steel, spring steel, such as: 20CrMnTi 60SiMn, (with the C content expressed in parts per million).

◆Stainless steel, alloy tool steel (with a few thousandths of C content), such as: 1Cr18Ni9 one thousandth (i.e. 0.1% C), stainless C ≤ 0.08% such as 0Cr18Ni9, ultra-low carbon C ≤ 0.03% such as 0Cr17Ni13Mo.

Labeling method

The American Iron and Steel Institute is a three-digit number to label the various standard grades of malleable stainless steel. Among them.

① austenitic stainless steel with 200 and 300 series of numbers marked, for example, some of the more common austenitic stainless steel is marked with 201, 304, 316 and 310.

② Ferritic and martensitic stainless steels are indicated by numbers in the 400 series. Ferritic stainless steel is marked by 430 and 446, martensitic stainless steel is marked by 410, 420 as well as 440C, duplex (austenitic-ferritic).

③ Stainless steels, precipitation-hardening stainless steels, and high-alloys containing less than 50% iron are usually named using patented names or trademarks.

Standard classification

4-1 classification classification.

① national standard GB ② industry standard YB ③ local standard ④ enterprise standard Q/CB

4-2 Classification.

① product standards ② packaging standards ③ method standards ④ basic standards

4-3 Standard level (in three levels).

Y level: international advanced level I level: international general level H level: domestic advanced level

4-4 National standard.

GB1220-84 stainless bar (I level) GB4241-84 stainless welded disc garden (H level)

GB4356-84 stainless welded disc garden (Class I) GB1270-80 stainless pipes (Class I)

GB12771-91 Stainless welded pipe (Y grade) GB3280-84 Stainless cold plate (I grade)

GB4237-84 stainless hot plate (Grade I) GB4239-91 stainless cold strip (Grade I)

New Products

200 Series D7S

Product description: The nickel content of D7S is about 2.5%, which is slightly lower than the nickel content of D11, and the counting price is also relatively low. 1% nickel content will be the key to the market supply of D7S to some extent, so it will also be an important part of the sales plan in the field of competitive, high overall quality stainless steel with high usage rate.

Application areas: the target market for new products such as stainless steel kitchen appliance equipment and other areas to start the marketing and sales plan for stainless steel tubes.


Product description: The material has a tensile strength of 980 to 1180 MPa and a maximum working temperature of 90°C.

Application areas: pipes for harsh subsea environments

Boiler type

Product description: Super (super) critical unit is the basis of modernization of power generation equipment and energy saving and emission reduction. Among the important pressurized parts of super (ultra) critical boilers, the parts with the highest working temperature and the most severe working environment are superheater and reheater. Previously, all such materials used in China were imported from abroad, and there are only 10 international manufacturers of steel materials with limited capacity, large shortage of such materials, expensive imports, and procurement difficulties, supply exceeds demand, seriously affecting the production of Chinese ultra-supercritical boilers and the development of electrical energy. China’s current demand for power station boiler tubes is about 30,000 tons per year, and with the continuous improvement of ultra (super) critical power generation technology, the demand is expanding year by year. Several large domestic enterprises have invested a lot of human and financial resources in the research and development and production of such products, and have made considerable achievements. On the one hand, it has made its own contribution to the development of the country’s electric power industry, and at the same time, it has also brought considerable economic benefits to the enterprises.

Application areas: power station boiler industry, mainly the key parts such as superheater and reheater high temperature section.

Specification table

Duplex stainless steel

Product description: This stainless steel has good corrosion resistance in urea-carbamate solution and possesses high stress corrosion cracking resistance in chloride environment. At the same time, this duplex stainless steel has excellent mechanical properties and can be used in the construction of plants with high safety requirements.

Application areas: chemical industry, construction industry.

Steel pipe size and allowable deviation

Deviation Grade

Allowable deviation of standardized outer diameter


±1.5%, minimum ±0.75 mm


±1.0%. Min ±0.50 mm


±0.75%. Min ±0.30 mm


±0.50%. Min. ±0.10 mm

Weight calculation editorial broadcast

Hydraulic test pressure formula for stainless steel welded pipe for fluids (GB/T1277-2008).


where: P – test pressure, MPa.

R – stress, taking 50% of the yield point, MPa.

S – nominal wall thickness of the steel pipe, mm.

D – nominal outside diameter of the steel pipe, mm.

W = (OD – wall thickness) × wall thickness × 0.02491 = KG/M (weight per meter).

Stainless steel pipe executive standard editorial Podcast

Stainless steel pipe

Stainless steel pipe(2 sheets)

GB/T14976-2012 seamless stainless steel pipe for fluid transportation

(replacing GB/T14976-2002 replacing GB/T14976-1994 replacing GB2270-1980)

GB/T14975-2012 seamless stainless steel pipe for structure (replacing GB/T14975-2002)

GB13296-2013 Stainless steel tubes for boiler tubes and heat exchangers

(GJB2608-96) (YB676-73) Structural tubes and thick-walled seamless steel tubes for aviation

(GJB2296-95) (YB678-71) Stainless steel tubes for aviation

(YB/T679-97) (YB679-71) 18A hollow rivet thin-walled seamless steel pipe for aviation

(GJB2609-96) (YB680-71) Structural and thin-walled seamless steel tubes for aviation

(YB/T681-97) (YB681-71) 20A thin-walled seamless steel pipe for aviation ducts

GB3090-2000 small diameter stainless steel pipe

GB5310-2017 Seamless steel pipe for high pressure boiler

GB3087-2008 Low and medium pressure boiler tube

GB3089-2008 Stainless steel pipe with very thin wall for acid resistance

GB9948-2013 Seamless steel pipe for petroleum cracking

ASTM A213 Ferritic and austenitic alloy tubes for boilers and heat exchangers

ASTM A269 Austenitic stainless steel tubes and welded tubes for general use

ASTM A312 Seamless austenitic stainless steel tubes and pipes welded tubes and pipes

ASTM A450 General requirements for carbon, ferritic and austenitic alloy steel tubes and pipes

ASTM A530 General requirements for ferrous and alloy steels for special purposes

ASTM A789 General requirements for seamless and welded steel tubes and pipes of carbonitic austenitic stainless steel

JIS G3456-88 Stainless steel pipes for mechanical structures

JIS G3448-88 Stainless steel pipes for general pipelines

JIS G3459-88 Stainless steel pipes for pipelines

JIS G3463-88 Stainless steel pipes for boilers and heat exchangers

Q/HYAD Seamless steel pipe for chemical industry

(0Cr18NI11T) Q/HYAD Cr18Ni5MO3Si2 duplex stainless steel seamless steel pipe

Application requirements

Automotive industry

The main use of stainless steel is the exhaust system, accounting for more than 1/2 of the total amount of automotive stainless steel, 80% of ferritic stainless steel. The exhaust gas produced by the car engine flows through the exhaust gas intake pipe, front pipe, hose, converter, center pipe and finally from the muffler. Commonly used steel grades for exhaust system are 409L, 436L, etc. Automotive mufflers mainly use stainless steel welded pipes. It is estimated that the stainless steel pipe used in automobiles accounts for about 1.5% of the entire downstream usage of stainless steel pipe, while the use ratio of seamless stainless steel pipe and welded pipe is about 2:1.

Petrochemical industry, including the fertilizer industry

The demand for stainless steel pipe is great, the industry mainly uses stainless steel seamless pipe, specifications include: 304, 321, 316, 316L, 347, 317L, etc., the outer diameter in ¢18-¢610 or so, wall thickness in 6mm-50mm or so (generally is the choice of specifications in Φ159mm or more low and medium pressure transmission pipe), the specific application areas are: furnace tube, material transfer tube, heat exchanger tube, etc. Heat exchanger tube, etc.

Water and gas and other fluid transportation

Stainless steel pipeline and its water transmission equipment is the most advanced basic water purification material in the world today, with strong anti-corrosion performance, cast iron pipes, carbon steel pipes, plastic pipes, etc., can not be compared with it.

Water preparation, storage, transmission, purification, regeneration, desalination and other water industry’s best choice of materials. The annual demand is about 25,000 tons.

Equipment manufacturing and maintenance

The annual consumption of stainless steel pipe is more than 20,000 tons. This type of industry mainly uses sanitary or antibacterial grade stainless steel pipe. Sanitary seamless tubes made of imported SUS304 and 316L can meet the special requirements of various media in food and biopharmaceutical fields. Antimicrobial stainless steel has the advantages of stainless steel and good antibacterial properties, and the demand for kitchen equipment, workbenches and utensils in the food industry, medical equipment, tableware and hanging towel brackets in daily life, brackets in refrigerated cabinets and other fields is increasing.

Material classification

Stainless steel pipe can be divided into Cr system (400 series), Cr-Ni system (300 series), Cr-Mn-Ni (200 series) and precipitation hardening system (600 series) according to the composition.

200 series – Cr-Ni-Mn austenitic stainless steel 300 series – Cr-Ni austenitic stainless steel.

301 —– has good ductility and is used for forming products. Can also be rapidly hardened by mechanical processing. Good weldability. Wear resistance and fatigue strength are better than 304 stainless steel.

302 —– has the same corrosion resistance as 304, but is stronger due to its relatively high carbon content.

303 —– is easier to machine than 304 by adding small amounts of sulfur and phosphorus.

304—– is 18/8 stainless steel. GB grade is 0Cr18Ni9. 309- has better temperature resistance than 304.

316 —– is the second most widely used steel grade after 304, mainly used in the food industry, pharmaceutical industry and surgical equipment, with the addition of molybdenum to give it a special structure that resists corrosion. SS316 is commonly used for nuclear fuel recovery devices. 18/10 grade stainless steel tubes are also usually qualified for this application.

Type 321 – similar to 304 except that the addition of titanium reduces the risk of corrosion in the material welds.

400 Series – Ferritic and martensitic stainless steels.

408 – Good heat resistance, weak corrosion resistance, 11% Cr, 8% Ni.

409-The cheapest type (British and American), usually used as automotive exhaust, ferritic stainless steel (chromium steel).

410-Martensitic (high strength chromium steel), good wear resistance, poor corrosion resistance.

416 – added sulfur to improve the processing properties of the material.

420-“Cutting tool grade” martensitic steel, similar to Brinell high chromium steel, the earliest stainless steel. Also used for surgical knives and can be made very bright.

430 – Ferritic stainless steel, used for decorative purposes, e.g. for car accessories. Good formability, but less resistant to temperature and corrosion.

440 – High strength cutting tool steel, slightly higher carbon content, after appropriate heat treatment can be obtained after high yield strength, hardness can reach 58HRC, belong to the hardest stainless steel among. The most common application example is “razor blade”. There are three common types: 440A, 440B, 440C, and 440F (easy to work with).

500 Series – Heat resistant chromium alloy steel.

600 Series – Martensitic precipitation hardening stainless steel tubes.