Seamless pipe

Seamless pipe is produced by heating a round billet of steel and then piercing it with a bullet-shaped piercer, over which the steel is stretched.

Seamless pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids.

ASTM Seamless Pipe

ASTM Standards can be purchased as a digital library subscription or individually from ASTM and other qualified standards providers.

DIN/EN Steel pipes

DIN Standards are the results of work at national, European and/or international level.

The method of extending the service life of seamless pipe

Seamless steel pipes have hollow sections and are widely used as pipes for conveying fluids, such as pipes for conveying oil, natural gas, gas, water and certain solid materials. The seamless pipe has a certain corrosion resistance, but in order to prolong the service life of the seamless pipe in some extreme environments, it is necessary to remove the oxide layer on the surface of the product. The main cleaning method is pickling. After cleaning, electrolytic cleaning is required again.

  1. The seamless steel pipe must wear labor protection supplies before pickling. The on-site working environment should also be checked in detail, mainly to check whether the hoisting of the steel pipe is intact, and work can only be carried out after confirming that it is intact.
  2. When pickling seamless steel pipes, the pickling method is mainly hydrochloric acid pickling. Usually, the content of hydrochloric acid is preferably 18% to 20%.
  3. The staff also need to know the concentration and temperature of the acid solution in this tank and the tonnage of the pickling pipe before operation.
  4. The weight of pickling steel pipe is controlled between 2-5 tons each time, and the time is controlled within 5-15 minutes. Time needs to be adjusted according to body weight. During the pickling process of steel pipes, frequent vibrations are also required. When lowering the pipe into the acid tank, the steel pipe should be tilted to prevent accidental injury by hydrochloric acid.

The seamless pipes stored in the warehouse waiting to be put into use need to do the following work

The warehouse shall not be piled together with acid, alkali, salt, cement and other materials that are corrosive to steel. Steel materials of different types should be stacked separately to prevent mixing and contact corrosion.

  1. Large steel sections, rails, steel plates, large-diameter steel pipes, forgings, etc. can be stacked as needed.
  2. Some small steel products, thin steel plates, steel strips, silicon steel sheets, small-diameter or thin-walled steel pipes, various cold-rolled and cold-drawn steel products, high-priced and easily-corroded metal products can be stored in the warehouse.
  3. The warehouse should be selected according to the geographical conditions. Ordinary closed warehouses are generally used, that is, warehouses with ceilings, walls, tight doors and windows, and ventilation devices.

Quality problems of seamless steel pipes

There are two types of factors that affect the quality of seamless steel pipes: steel quality and rolling process factors.

Factors in the rolling process are discussed here. The main influencing factors are: temperature, process adjustment, tool quality, process cooling and lubrication, removal and control of sundries on the surface of rolled parts, etc.

1. Temperature

Temperature is the most important factor affecting the quality of seamless steel pipes. First of all, the uniformity of the heating temperature of the tube blank directly affects the wall thickness uniformity and inner surface quality of the perforated capillary, which in turn affects the wall thickness quality of the product. Secondly, the temperature and uniformity of the steel pipe during the rolling process (especially the final rolling temperature) are related to the mechanical properties, dimensional accuracy and surface quality of the delivered product in the hot-rolled state, especially when the steel billet or lamp tube is overheated or even When overburned, it will cause waste. Therefore, in the production process of hot-rolled seamless pipes, heating and controlling the deformation temperature in strict accordance with the process requirements are the first work that must be done.

2. Process adjustment

Process adjustment and work quality mainly affect the geometric shape and appearance quality of steel pipes.

For example, the adjustment of the piercing machine and the rolling mill affects the wall thickness accuracy of the product, and the adjustment of the sizing machine is related to the accuracy and straightness of the product's outer diameter. Moreover, process adjustment also affects whether the rolling process can be carried out normally.

3. Tool quality

The quality and stability of the cutting tool are directly related to the dimensional accuracy, surface quality and cutting tool consumption of the product can be effectively controlled; the quality of the mandrel surface treatment (chrome plating) first affects the inner surface of the seamless steel pipe, and secondly affects Mandrel consumption and production costs.

4. Process cooling and lubrication

The cooling quality of the piercing head and rolls not only affects their life, but also affects the quality control of the inner and outer surfaces of the finished product. The cooling and lubrication quality of the mandrel first affects the inner surface quality, wall thickness accuracy and mandrel consumption of the seamless steel pipe; it also affects the load during rolling.

5. The removal and control of sundries on the surface of rolled parts refers to the timely and effective removal of iron sheets on the inner and outer surfaces of capillaries and waste pipes, and the control of reoxidation before rolling deformation. Nitrogen blowing in the inner hole of the capillary, borax spraying, pipe rolling and high-pressure water descaling at the entrance of fixed (reduced) diameter, effectively improving and enhancing the quality of the internal and external surfaces.

Steel Pipe & Tubing - All you need to know

Steel Pipe & Tubing seem similar at first blush and in fact they share many characteristics but they also have some important differences.

Definitions

Steel Tubing is a hollow steel shape intended for structural purposes and made from carbon, stainless, or galvanized steel further divided as:

Mechanical Tubing is used in low stress applications such as fences, kitchens, restaurants, hospitals, solar panels and made with wall thicknesses up to 10 gauge.

Structural Tubing is for high stress structural application like bridges, buildings, roll cages, and underwater platforms with wall thickness from 3/16" and up. It is often referred to as Hollow Structural Sections or just the acronym HSS.

Pipe is a hollow structure that is intended to carry material such as liquids, gasses, or even solids. Its wall thickness is described by its Schedule and it is often broken down by type using the method of manufacturing it, either ERW or Seamless

How it's made

Both Tubing and Pipe are manufactured by the first two methods below. The third is reserved for Tubing only.

Electric Resistance Welded, often abbreviated as ERW, is a process that uses specific machinery to shape the pipe and tubing. A continuous steel sheet is unwound from a coil and shaped using contoured rollers, forcing the edges together under pressure. These edges are then welded together by heating the material to over 2,000 degrees. After welding, the pipe or tubing is cut into the exact size needed.

Seamless Pipe (and tubing) is made by extruding a steel block or by drilling a solid steel bar. Next, the extrusion or the drilled steel bar is cold drawn through a dye to achieve the diameter and thickness needed. Because this process can cause mechanical hardening, sometimes the material is annealed and straightened as a final process. Seamless Pipe & Tubing is subdivided as:

Cold Drawn Seamless, or CDS, exhibits precise tolerances and a good surface finish.

Hot Finished Seamless, or HFS, has less critical tolerances and somewhat scaly finish and is not as strong as CDS.

For Drawn over Mandrel, or DOM tubing, the first stages of manufacturing are identical to ones used to make electric resistance welded tubing, but in the finishing stages the entire flash weld is taken out and the tube is cold drawn over a mandrel. A mandrel is a round object against which material can be forged or shaped. The cold drawn process provides the tube with better dimensional tolerances, improved surface finish and the strongest weld strength achievable.

Pipe Sizes

Pipe Size is specified with two non-dimensional numbers:

Both the size and schedule are required to accurately specify a particular piece of pipe.

Nominal Pipe Size (NPS) is the current North American Set of standard sizes for pipes used for high and low pressures and temperatures. A further discussion of this is here.

Iron Pipe Size (IPS) was an earlier standard than NPS to designate the size. The size was the approximate inside diameter of the pipe in inches. Each pipe had one thickness, named (STD) Standard or (STD.WT.) Standard Weight. There were only 3 wall thicknesses at the time. In March 1927, the American Standards Association created a system that designated wall thickness based on smaller steps between sizes and introduced Nominal Pipe Size which replaced Iron Pipe Size.

Schedule Number for wall thickness ranges from SCH 5, 5S, 10, 10S, 20, 30, 40, 40S, 60, 80, 80S, 100, 120, 140, 160, STD, XS (Extra Strong) AND XXS (Double Extra Strong).

Other Pipe and Tubing Terms of Interest

BPE – Black Plain End Pipe

BTC – Black Threaded & Coupled

GPE – Galvanized Plain End

GTC – Galvanized Threaded & Coupled

TOE – Threaded One End

Typical Pipe Coatings & Finishes:

Galvanized – Covered with a protective zinc coating on steel to prevent the material from rusting. The process can be hot-dip-galvanizing where the material is dipped in molten zinc or Electro-Galvanized where the steel sheet from which the pipe is made was galvanized during production by an electro-chemical reaction.

Uncoated – Uncoated Pipe

Black Coated – Coated with a dark colored iron-oxide

Red Primed – Red Oxide Primed used as a base coat for ferrous metals, gives iron and steel surfaces a layer of protection

Sunny Steel explains Seamless steel pipe

Seamless pipes are derived from solid steel that is in sheet or bar form and is formed into a solid round shape known as “billets” which are then heated and cast over a form such as a piercing rod to create a hollow tube or shell.

How to deistinguish pipe material

Material requirements

SMLS pipe is produced by heating a round billet of steel and then piercing it with a bullet-shaped piercer, over which the steel is stretched. This is followed by rolling and drawing to produce the desired dimensions. The final product is hydrostatically tested, inspected, coated if required, and stenciled with the specification. SMLS pipe is used in high-pressure, most critical locations and under most severe operating conditions. SMLS pipe is supplied according to ASTM Specifications A53, A106, A333, A312, A358, etc., and API 5L pipe

Sizes: 1/8″ (3.175 mm) nominal to 26″ (660.4 mm) OD. Less than 2 3/8″ (60.325 mm) OD is known as pressure tubing that has different dimensional standards (wall thickness and diameter). SMLS pipe, where available, is used in oil and gas production facilities both onshore and offshore (other than transmission lines) less than 26″ (660.4 mm) OD.

Offshore Overview

How to deistinguish pipe material

Mills produce two types of line pipe, seamless and welded

Seamless pipe is formed from a cylindrical bar of steel. The bar is heated to a high temperature and then a probe is inserted to create a hole through the cylinder. The cylinder is then transferred to rollers which size the cylinder to the specified diameter and wall thickness. A few mills can produce seamless pipe up to 24-in in diameter. For small diameter pipe, seamless pipe is common but unit costs are high and availability is usually limited. As pipe diameter increases, welded pipes are more economical.

In welded pipe, welding is used to close the seam after forming a steel plate or coil into a cylindrical shape. The mill uses ultrasonic and/or radiological inspection methods to ensure the quality of the weld seam and initiates pressure tests on each joint of pipe to levels that exceed the proposed operating pressure. Welded pipe is classified based on how it is formed and the type of welding technique used.

Submerged arc weld (SAW) pipe uses filler metal in welding, whereas electric resistance welded/electric fusion welding (ERW/EFW) are no-filler metal processes. SAW is further classified into longitudinal (or straight) welding (L-SAW) and S-SAW means spiral (or helical) weld tube. Normally, medium diameter straight L-SAW has a single seam, and large diameter L-SAW uses a double seam.

ERW pipe is manufactured using electric current to heat the steel to a point at which the edges melt together to form a bond. This manufacturing process was introduced in the 1920s and utilized low-frequency alternating current to heat the edges, but was found to be vulnerable to seam corrosion and inadequate bonding. Today, high-frequency alternating current is used, also known as contact welding. EFW pipe refers to a process that uses an electron beam to direct kinetic energy to melt the workpiece to form the weld.

PIPs are manufactured using two pipes separated by insulation and are used to maintain the temperature of the fluids to prevent the formation of hydrates, reduce wax deposition, or to reduce the pressure drop by reducing the viscosity of heavy crudes (Cochran, 2003).

Rigid flowlines are manufactured from carbon steel or a high-performance steel alloy, with additional coatings providing corrosion protection and insulation. Flexible flowlines have the same applications as rigid flowlines but are manufactured differently, using composite layers of steel wire and polymer sheathing that provide high flexibility (Box 1.3). A typical 8-in diameter flexible pipe, for example, can be safely bent to a radius of two meters or less. This flexibility is important for risers and flowlines laid on uneven seabeds and permits spooling on a reel or carousel in installation. The preference for using a rigid or flexible flowline is driven by design requirements, installation constraints, cost, schedule, and other factors.

Flexible Pipeline Configuration

A flexible pipe is a configurable product made up of several independent layers tailored to each development (Fig. 1.21). Flexible pipes are used for risers, flowlines, and jumpers in offshore operations, but because the unit cost is much more expensive than a carbon steel pipe, its use is often limited to special applications and small quantities (Tuohy et al., 2001).

Flexible pipe is manufactured by wrapping several intertwining layers of stainless steel and special polymers. The helically wound steel wires give the pipe its high-pressure resistance and bending characteristics, and since the steel wires are not in direct contact with the conveyed fluid, they do not require the same corrosion resistance as steel pipe. Variation in the choice of materials, the number and order of layers, and manufacturing process depends on the conditions and operating environment.

The components of an unbonded flexible pipe are as follows:

Carcass. The carcass forms the innermost layer and is the conduit for fluid transport. It is commonly made of a stainless steel flat strip that is spirally wound and formed into an interlocking profile. The main function of the carcass is to prevent pipe collapse due to hydrostatic pressure in the annulus.

Internal polymer sheath. The internal polymer sheath provides a barrier to maintain the bore fluid integrity. Common materials used include Polyamide-11 (Rilsan), high-density polyethylene, cross-linked polyethylene, and PVDF.

Pressure armor. The pressure armor, as its name implies, is wound around the internal polymer sheath for protection and is made of interlocking wires or wire strips. Its role is to withstand the hoop stress in the pipe wall caused by the fluid pressure.

Tensile armor. The tensile armor layers are used to resist tensile loads, to support the weight of all the pipe layers, and to transfer the load through the end fitting to the structure. The tensile armor layers are cross-wound in pairs and in high tension applications, say in a deepwater riser, may require the use of four tensile armor layers.

External polymer sheath. The main function of the external sheath is as a barrier against seawater and is often made of the same materials as the internal polymer sheath. External sheaths also provide protection against clashing with other objects during installation.

Other layers. Antifriction and antiwear tape are wound around the armor layers to reduce friction and wear of the wire layers when they rub past each other as the pipe flexes from external loads. Antiwear tapes are used to ensure that the armor layers maintain their wound shape and prevent the wires from twisting out of their configuration, a phenomenon called birdcaging that is a result of hydrostatic pressure causing axial compression in the pipe. Additional layers of material with low thermal conductivity can be applied to obtain specific thermal insulation properties.

Characteristics

Seamless steel pipe for the use of engineering and construction is very widely, it is a hollow steel strip no seams, it is mainly used to transport liquids pipelines, different look and general steel,one of those heavy type steel, it has a strong resistance to corrosion, resistant to general corrosion.

  • high precision can do small batch production.
  • smaller diameter.
  • weldability strong, high compression capability.
  • steel pipe superior performance, relatively dense metal.
  • Steel Cross area is more complex.
  • high precision cold drawn products, good surface quality.

Some of the differences between Seamless steel pipes and welded tubes are:

A Seamless steel pipe is extruded and drawn from a billet whereas a welded tube is produced from a strip that is roll formed and welded to produce a tube.

  • Since a Seamless steel pipe offers a higher range of safety measures it is more expensive than a welded tube.
  • A Seamless steel pipe is relatively short in length, whereas welded tubes can be manufactured in long continuous lengths.
  • A Seamless steel pipe generally doesn't show any sign of corrosion until and unless it is subjected to a highly corrosive environment, whereas the weld area in the welded tube is much more prone to corrosion attacks.
  • A welded area is considered to be inhomogeneous, thus it exhibits a different malleability and less corrosion resistance as well as greater dimensional variation.
  • A Seamless steel pipe eliminates any such issues and thus offers high corrosion resistance.

Mechanical properties:

The mechanical properties of the seamless steel tube is a important indicator that ensure seamless pipe end-use properties (mechanical properties), which depends on the chemical composition and heat treatment of steel.

In steel standards, according to different requirements, it provide the tensile properties (tensile strength, yield strength or yield point elongation) and hardness.

① Tensile strength (σb)
During stretching, when pull off the bear most strongly (Fb), divided by the original cross-sectional area (So) from the stress (σ), known as the tensile strength (σb), units of N/mm2 (MPa). It said the maximum capacity resist destruction of metallic materials under tension.

② Yield point (σs)
Yield the phenomenon of metal materials, the sample does not increase during the tensile force (remains constant) and continue elongation stress is known as the yield point. If the force drop occurred, you should distinguish between upper and lower yield point. The yield point of the unit is in N/mm2 (MPa). On yield point (σsu):Sample to yield the maximum stress and force the first drop; lower yield point (σsl): yield minimum stress in the stage when excluding the initial transient effect.

③ Elongation (σ)
In the tensile test, the specimen fractured a percentage of the gauge to increase the length of the original gauge length, called elongation. Σ, said the unit is%.

(4) Cross-section contraction rate (ψ)
In the tensile test, the percentage of the specimen fractured its shrink the diameter at the cross-sectional area of the maximum reduction and the original cross-sectional area is known as section shrinkage. Ψ expressed in%.

⑤ Hardness testing
Metallic materials against hard objects indentation of the surface, known as hardness. accoring to the test method and scope of application, the hardness can be divided into brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, hardness and high temperature hardness. Commonly used for pipe, Brinell, Rockwell, Vickers hardness of three kinds.


Process

Cold drawn seamless steel tube deformed process

Cold Drawn Seamless Mechanical Tubing (CDS) is a cold drawn 1018/1026 steel tube which offers uniform tolerances, enhanced machinability and increased strength and tolerances compared to hot-rolled products.

Cold drawn seamless steel tube deformed process

Cold drawn steel tube is with hot-rolled steel coil as raw material, and tandem cold rolling pickled to remove oxide scale, its finished rolling hard roll, rolling hard volumes due to the continuous cold deformation caused by cold hardening strength, hardness increased indicators declined tough plastic, stamping performance will deteriorate, which can only be used for simple deformation of the parts.

Rolling hard roll can be used as the raw material of the hot-dip galvanizing plant, hot dip galvanizing line set annealing line. Rolling hard roll weight is generally 6 to 13.5 tons, the coil diameter of 610mm.

Hot rolled seamless steel pipe deformed process

Hot-rolled seamless steel pipe production base deformation process can be summarized as three stages: perforation, extension and finishing.

Hot rolled seamless steel pipe deformed process

The main purpose of the perforation process is to become a solid round billet piercing hollow shell. Capillary in the specifications, accuracy and surface quality can not meet the requirements of the finished product, further improvements are needed to deform the metal through. The main purpose of the stretching machine is further reduced sectional view (main compression wall) for a larger axial extension, so that the capillary improved dimensional accuracy, surface quality and organizational performance.

After stretching machine rolled steel pipe shortage collectively need further molding mill in order to achieve the requirements of the finished pipe. Rolled steel due to pass in the method widely used in the production of seamless steel tubes.

So far, due to the method pass rolling steel can be divided into two categories: core pension without rolling rolling (hollow body rolling), and with the mandrel. Sizing machines, reducing mill and stretch reducing mill belonging to the hole without mandrel type continuous rolling mills are generally coffin. Its main purpose is to reduce the diameter of the deformation process or sizing get finished steel, the wall thickness of process control, can make thinning, thickening or nearly unchanged.

All the traditional hole-type rolling machine with mandrel belong to extend machine. The main purpose is to reduce the deformation process perforated capillary wall thickness and outer diameter roll passes in the deformation zone and the mandrel posed, for a larger axial extension. At the same time a certain improvement in the organization, performance, accuracy, surface quality.

Cut to Length

Before cutting pipe and tubing

No matter the material, measure the diameter of the pipe or tube to be cut to ensure that you use the right-size tube cutter for the job. When determining how to make a straight cut, use a tape measure and a pencil or other writing instrument to mark on the surface where you want to cut. If possible, mark around the circumference of a pipe, especially when cutting with a handsaw. Ensure that a cut is as straight as possible by securing the pipe with a vise, clamp, miter box or even duct tape to keep the length from shifting out of place while cutting.

After cutting pipe and tubing

  • Unless a cut is perfectly clean, you should expect to remove burrs from around the edge, especially after sawing.
  • Use a deburring tool to clean the edge after tube cutting.
  • You may opt to use a metal file on the cut of a metal pipe.
Cut to length

The main manufacturing technology of seamless carbon steel pipe

1.Plug rolling production

The production equipment consists of punching machine, automatic pipe rolling machine, coiling machine, sizing machine and reducing machine. The round tube is inserted into the hollow of the thick-walled tube, and the axes of the two rollers form an oblique angle with the rolling line. In recent years, the inclination angle has increased from 6° to 12° to 13° to 17°, increasing the speed of the punch. When producing structural seamless pipe with a diameter greater than 250mm, secondary perforation is used to reduce the thickness of the hollow billet wall. New technologies have also been developed to enhance the perforation process and improve the quality of the capillary.

2. Continuous rolling production

The production equipment includes punching machine, continuous rolling mill, and tension reduction machine. The round billet is pierced into a hollow billet, then inserted into the mandrel, and continuously rolled by 7 to 9 two-roll mills. After rolling, the mandrel bar is taken out and reheated to reduce tension. In 2014, the annual output of 140mm continuous rolling mills is 0.4 to 600,000 tons, which is 2 to 4 times that of plug mills. The characteristics of this unit are suitable for the production of steel pipes with a diameter of 168mm or less. However, the equipment investment is large, the installed capacity is large, and the processing and manufacturing are complex.

3. Three-roll rolling production

Three-roll rolling production is mainly used to produce thick-walled seamless steel pipes with high dimensional accuracy. The wall thickness accuracy of the seamless steel pipe produced by this manufacturing process can reach plus or minus 5%, and the pipe accuracy is twice that of the seamless steel pipe produced by other methods. This manufacturing technique developed rapidly with the invention of the new three-high skew rolling mill in the 1960s. The new type of rolling mill is characterized by rapidly rotating the inlet rotary rack to change the expansion angle of the tail, thereby preventing the triangle from appearing at the tail, and expanding the ratio of the outer diameter to the wall thickness of the production varieties from 12 to 35, which can not only produce thin-walled seamless welded steel pipes , but also can improve production capacity.

4. Extrusion tube production

The peeled round base is first perforated or expanded, then heated by induction heating or a salt bath, coated with lubricant, and loaded into the extruder. The metal is squeezed into the pipe through the circular gap between the mandrel and the tip of the pen. This manufacturing process is mainly used for the production of superalloy tubes, specialty tubes, composite tubes and non-ferrous metal tubes. It has a wide range of production but low volumes. The production of extruded tubes has also grown in recent years due to improvements in die materials, lubricants and extrusion speeds.

5. Cold rolling (cold drawing) production

This manufacturing process is used to produce small-diameter precision-shaped thin-walled low-carbon steel pipes. It is characterized by the use of multi-stage cycle manufacturing technology. In the 1960s, it began to develop in the direction of high speed, multi-line, long stroke and long tube blank. In addition, small roller mills have also been developed, mainly for the production of precision tubes with a thickness of less than 1mm. The cold rolling equipment is complex, the tool processing is difficult, and the specification conversion is not flexible. And usually a combined process of cold rolling and cold drawing is used, that is, cold rolling is used to reduce the wall thickness to obtain larger deformation, and cold drawing technology is used to obtain various specifications.


Application

Alloy steel pipes are ideally suitable for chemical, petrochemicals, and other energy-related applications.

The alloy steel pipe adopts high quality carbon steel, alloy structural steel and stainless & heat resisting steel as raw material through hot rolling or cold drawn to be made.

Alloy steel can be used in process area where carbon steel has limitation such as

  • High-temperature services such as heater tubes
  • Low-temperature services such as cryogenic application
  • Very high presser service such as steam header

As an important element of steel products, alloy steel pipe can be divided into seamless steel pipe and welded steel pipe according to the manufacturing technique and tube billet shape.

Here you can see the common alloy steel grade that you will come across.

  • For Pipes: ASTM A335 Gr P1, P5, P11, P9
  • For Wrought Fittings: ASTM A234 Gr.WP5, WP9, WP11
  • For Forged Fittings: ASTM A182 F5, F9, F11 etc.

Why the application of alloy steel pipe is wider than others

application

There are many kinds of materials used for transport in industrial production. Specifically we will have more choices and it is not limited to the use of alloy steel pipe. But even in the face of more choices, many people tend to choose alloy steel pipe. People make their own choices will have their own reasons. This means the alloy steel pipe application has its own advantages. Compared with transmission lines made of other materials, after it meets the basic application requirements, its quantity is lighter. Then in the practical application of alloy steel pipe, it will have more advantages because of this. Besides its physical characteristic advantage, it also has economic advantages. The wide application of alloy steel pipe is with kinds of reasons. So in practical usage, we can exploit the advantages to the full, in this way can we get more profits in these applications of alloy steel pipe.

What requirements should alloy steel pipe application meet

The transportation of kinds of gases or liquids in production needs to rely on alloy steel pipe. This shows that the actual role of alloy steel pipe application is important. High temperature resistant and low temperature resistant is the tolerance of temperature. In the practical application of alloy steel pipe, there will be many materials need to be transported. However their temperatures are not the same. So this can be the basic requirement to alloy steel pipe. It needs more corrosion resistance. Corrosion resistant material is the best material during transporting, because it is corrosion resistant. So it can be used in more occasions. And it is definitely very convenient for users.

The biggest advantages of alloy steel pipe

Can be 100% recycled, environmentally friendly, energy-saving, resource conservation, national strategy, national policy to encourage the expansion of the field of application of high-pressure alloy pipe. Of alloy steel pipe total consumption accounted steel in the proportion is only half of the developed countries, to expand the field of use of the alloy steel pipe to provide a wider space for the development of the industry. The future needs of the average annual growth of China’s high-pressure alloy steel pipe long products up to 10-12%.

Specification, standard and identification of alloy steel pipes

Alloy Steel pipe contains substantial quantities of elements other than carbon such as nickel, chromium, silicon, manganese, tungsten, molybdenum, vanadium and limited amounts of other commonly accepted elements such as manganese, sulfur, silicon, and phosphorous.

Industries We Serve

Our team of experienced sales specialists proudly partners with gas and chemical processors, power generation plants, oil refineries, and related industries to offer piping components and value-added services.

The biggest advantages of alloy steel pipe can be 100% recycled, environmentally friendly, energy-saving, resource conservation, national strategy, national policy to encourage the expansion of the field of application of high-pressure alloy pipe. Of alloy tube total consumption accounted steel in the proportion is only half of the developed countries, to expand the field of use of the alloy tube to provide a wider space for the development of the industry. According to the Chinese Special Steel Association alloy pipe Branch Expert Group, the future needs of the average annual growth of China’s high-pressure alloy pipe long products up to 10-12%.


Inspection

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.

PMI

identification of the chemical composition of the metal used to manufacture the fitting. Uses PMI sensors, including X-ray fluorescence or optical emission spectrometry.

PMI
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PMI

Size measurement

Size measurement
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Seamless pipes with compound bevels as per ASME B16-25 And ASTM A333

ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe

Delivery

Steel pipe delivery status(condition)

Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).

Condition on delivery of steel pipe

Term Symbol Explanation
Cold-finished/hard (cold-finished as-drawn) BK No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft (lightly cold-worked) BKW After the last heat treatment there is a light finishing pass (cold drawing) With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.
Annealed GBK After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
Normalized NBK The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum.

The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.

Cold rolled steel coil substrate products deep processing of high value-added products. Such as electro-galvanized, hot dip galvanized, electro-galvanized fingerprint resistant, painted steel roll damping composite steel, PVC laminating steel plates, etc., so that the excellent quality of these products has a beautiful, high resistance to corrosion, has been widely used.

Cold rolled steel coil finishing after annealing, cut the head, tail, trimming, flattening, smooth, heavy volume, or longitudinal clipboard. Cold-rolled products are widely used in automobile manufacturing, household electrical appliances, instruments, switches, buildings, office furniture and other industries. Steel plate strapping package weight of 3 to 5 tons. Flat sub-volume typically 3 to 10 tons / volume. Coil diameter 6m.

Packing

Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for sea-worthly delivery or as requested.

There are probably hundreds of different methods for packing a pipe, and most of them have merit, but there are two principles that are vital for any method to work prevent rusting and Sea transportation security.

Steel strips bunding for fixed pipes

Our packing can meet any needs of the customers.

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Placing steel pipes into containers

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FAQ

Q&A

Our team of experienced sales specialists proudly partners with gas and chemical processors, power generation plants, oil refineries, and related industries to offer piping components and value-added services.

The most important and desired changes in alloy steel are

Alloy steels are made by combining carbon steel with one or several alloying elements, such as manganese, silicon, nickel, titanium, copper, chromium and aluminum. These metals are added to produce specific properties that are not found in regular carbon steel. The elements are added in varying proportions (or combinations) making the material take on different aspects such as increased hardness, increased corrosion resistance, increased strength, improved formability (ductility); the weldability can also change.

Alloying Elements & Their Effects

Pipes, Tubes and Hollow Sections

Norms

Grade

Alloying Elements

Commonly used alloying elements and their effects are listed in the table given below.

Alloying Elements Effect on the Properties
Chromium Increases Resistance to corrosion   and oxidation. Increases hardenability and wear resistance. Increases high   temperature strength.
Nickel Increases hardenability. Improves   toughness. Increases impact strength at low temperatures.
Molybdenum Increases hardenability, high   temperature hardness, and wear resistance. Enhances the effects of other   alloying elements. Eliminate temper brittleness in steels. Increases high   temperature strength.
Manganese Increases hardenability. Combines   with sulfur to reduce its adverse effects.
Vanadium Increases hardenability, high   temperature hardness, and wear resistance. Improves fatigue resistance.
Titanium Strongest carbide former. Added to   stainless steel to prevent precipitation of chromium carbide.
Silicon Removes oxygen in steel making.   Improves toughness. Increases hardness ability
Boron Increases hardenability. Produces   fine grain size.
Aluminum Forms nitride in nitriding steels.   Produces fine grain size in casting. Removes oxygen in steel melting.
Cobalt Increases heat and wear   resistance.
Tungsten Increases hardness at elevated   temperatures. Refines grain size.

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【H】 Ceramic lined pipe

Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.

【H】 Cast basalt lined steel pipe

Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.

【H】 Ceramic Tile Lined Pipes

Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.

【H】 Rare earth alloy wear-resistant pipe

The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.

【H】 Tubes Erosion Shields

Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.

【H】 ASTM A213 T91 Alloy Tube

The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.