Boiler Tubes are metal tubes located inside of boilers that heat water in order to produce steam.
Boiler Tubes are metal tubes located inside of boilers that heat water in order to produce steam. There are two major types of tube boilers: water-tube boilers and fire-tube boilers. In water-tube boilers, water circulates inside the tubes and is heated externally by hot gases generated by the furnace.Download PDF
Boiler tubes refer to steel products that are open at both ends and have a hollow section. The ratio of its length to the surrounding area is large. According to the production method, it can be divided into seamless steel tubes and welded steel tubes. Wall thickness indicates a wide range of sizes, from capillary tubes with very small diameters to large-bore tubes up to several meters in diameter. Seamless steel pipes can be used in pipelines, thermal equipment, machinery industry, petroleum geological exploration, containers, chemical industry and special purposes.
Boiler seamless steel tubes are high-quality carbon steel, alloy steel and stainless heat-resistant seamless steel tubes used to manufacture high-pressure and above-pressure water tube boiler heating surfaces. These boiler tubes often work under high temperature and high pressure, and the tubes will be oxidized and corroded under the action of high temperature flue gas and water vapor. Therefore, steel pipes are required to have high durability, high oxidation resistance and good structural stability.
Industrial boiler tubes are mainly seamless steel tubes, because the various performance indicators of seamless steel tubes can fully meet the requirements of boiler applications. Although the cost is higher, its safety and reliability are higher. Welded steel pipes are generally used as low-pressure fluid delivery pipes within 2Mpa. High-temperature and high-pressure equipment such as industrial boilers must use seamless steel pipes, and the thickness of the pipe walls must be thickened accordingly.
Now, due to the rapid improvement of welding technology, welded steel pipes are also used in medium and low pressure boilers. For example, joints of friction welded steel pipes have the same microstructure. After the pipe joints are remelted by butt joints and fillet joints, it is difficult to observe the butt joint marks with the naked eye. The microstructure and quality of its parts are exactly the same.
Common problems in surface treatment and product processing of seamless steel pipes for high pressure boilers:
Boiler tubes are typically made from various types of steel, and the choice of material depends on factors such as the operating conditions, temperature, and pressure requirements of the boiler. The most commonly used materials for boiler tubes include:
Carbon Steel (ASTM A192, A210, A106, etc.): Carbon steel boiler tubes are widely used for low and medium-pressure boilers. They offer good tensile strength and are cost-effective. However, they are not suitable for high-temperature and high-pressure applications.
Alloy Steel (ASTM A213, A335, etc.): Alloy steel boiler tubes contain elements like chromium, molybdenum, and sometimes vanadium to enhance their properties. They are suitable for high-temperature and high-pressure boilers, making them ideal for power generation and industrial applications.
Stainless Steel (ASTM A213, A269, etc.): Stainless steel boiler tubes, especially grades like 304 and 316, are used in applications where corrosion resistance and hygiene are essential, such as in the food and pharmaceutical industries. They are also used in some high-temperature and high-pressure boilers.
Duplex Stainless Steel: Duplex stainless steel combines the properties of austenitic and ferritic stainless steels, providing excellent corrosion resistance and high strength. They are used in specific boiler applications where both properties are required.
Inconel and Incoloy Alloys: These high-performance nickel-based alloys are used in extremely high-temperature and corrosive environments, such as in supercritical and ultra-supercritical boilers in power plants.
Copper Alloys: Copper and copper-nickel alloys are used in specialized applications, such as in condenser tubes where excellent heat transfer properties are required.
While choosing boiler tubes, look for the following to pick out the right and good quality tubes:
High-pressure boiler tubes belong to the category of seamless steel pipes, such as seamless carbon steel boiler tubes, which have very high requirements on the tightness of the steel pipes.
The high-pressure boiler tube is employed in the manufacturing of seamless steel pipes for steam boilers operating at high temperatures and pressures, pipelines, furnace tubes for petrochemical applications, heat exchanger tubes, seamless steel pipes for pressure pipelines, high-pressure fertilizer equipment and pipelines, and seamless steel pipes for other chemical equipment.
The method of production is the same as that of seamless tubes, and the requirements are basically the same. However, the requirements for high-pressure boiler tubes are It is more demanding than ordinary boiler tubes. Because high-pressure boilers often operate in high-temperature and high-pressure environments, ordinary steel pipes cannot meet the operating requirements. This is one of the major reasons why special boiler tubes for high-pressure boiler tubes were born.
High-pressure boiler tubes are pivotal components not just for their ability to withstand elevated temperatures and pressures but also for their crucial role in resisting corrosion and oxidation. The operational environment of high-pressure boilers, frequently in contact with corrosive liquids, demands materials with exceptional resistance. Standard steel, when exposed to corrosive agents in water and steam, undergoes oxidation and corrosion, leading to substantial material wear. To mitigate building material costs, the initial material selection often leans towards anti-corrosion and anti-oxidation properties.
The performance expectations for these tubes are rigorous, emphasizing both rigidity and elasticity. High-pressure boilers, frequently subject to intense vibrations and impacts during operation, necessitate materials that surpass the capabilities of ordinary steel pipes.
The applications of high-pressure boiler tubes are diverse. They are prominently featured in the fabrication of water-cooled wall tubes and steam tubes, crucial components subjected to extremely high temperatures. In the automotive industry, these tubes find essential use in components like engine parts, where exposure to overheated steam and liquids makes ordinary pipes unsuitable due to the risk of corrosion.
Moreover, high-pressure boiler tubes play a key role in constructing ducts and air passages within high-pressure and ultra-high-pressure boilers. Their superior heat and gas conduction properties make them indispensable in ensuring the efficiency of these critical systems. These tubes are characterized by remarkable hardness, making them well-suited for deployment in demanding industrial testing environments.
In essence, the significance of high-pressure boiler tubes extends beyond their structural resilience; they embody a delicate balance of strength, corrosion resistance, and efficiency essential for the optimal functioning of high-pressure boiler systems.
Chinese national standards: GB5310-2017
American Society of Mechanical Engineers (ASME):ASME SA-106, ASME SA-192M, ASME SA -209M, ASME SA-210M, ASME SA -213M, ASME SA -335M
Deutsches Institut für Normung: DIN17175
Japanese Industrial Standards: JIS G3462
Sunny Steel has an extensive range of boiler and stay tubes available to meet your boiler tube requirements no matter how demanding.
Chinese National standards
American society of mechanical engineers
ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services.
Deutsche industrie normen
Deutsche industrie normen
Japanese industrial standards
The SA 213 Tp 304 Material consists of 18% chromium and carbon, manganese, phosphorus, sulfur, silicon and nickel in the composition.
SA213 TP304 is a range of minimum wall thickness pipe series. We supply the SA 213 TP 304 Pipes in different types, shapes and sizes. The SA 213 Tp 304 Material consists of 18% chromium and carbon, manganese, phosphorus, sulfur, silicon and nickel in the composition. There is also the molybdenum, nitrogen, niobium and titanium addition in trace quantities. The SA 213 Tp 304 Density is lower than the ordinary 304 material. It is 7.8 grams per cubic centimeter. We offer ASTM A213 TP 304 for high temperature services. Our 304 Stainless Steel Tube components are of less absolute roughness which means they could be used in high precision equipment and applications.
Austenitic stainless steels are presented in the ASME Boiler and Pressure Vessel Code with two sets of allowable stresses. The reason for this is their relatively low yield strength. The higher allowable stress values were determined at temperatures where the usage would be restricted by the short-time tensile properties.
The higher stresses exceed 62-1/2%, but do not exceed 90% of the yield strength. At these stresses, small amounts of plastic deformation can be expected. These higher stress values are usually used for super-heater and reheater tubing.
The Boiler Code lists maximum allowable stresses for varying temperatures depending on the individual austenitic stainless grade.
Variations of this 18 chromium, 8 nickel grade include 304L, 304LN, 304H and 304N. Each of these offers excellent corrosion and oxidation resistance along with high strength.
High strengths are maintained in the low carbon grades by controlling the nitrogen content.
T304 has higher carbon and a minimum solution annealing temperature to assure good long-time elevated temperature strengths. T304 grades are limited to 1650F under oxidizing conditions. Section I of the ASME Boiler Code lists allowable stresses up to 1500F.
SA213 TP316 Tube is a material standard for heat exchanger tubes that are made from 316 austenitic stainless steel.
The chromium nickel alloy also has molybdenum in its composition which makes it more corrosion resistant and heat resistant than the 304 material. ASME SA213 TP316 is the second most used pipe material in the world next to the 304 material. ASTM A213 TP316 Tube is an austenitic stainless steel but the 213 standard covers both the austenitic and ferritic steels.
Sunny Steel is a supplier of ASTM A213 Grade TP316 products in different standards and sizes. Our 316 Stainless Steel Tube can come with different finishing such as the 316 Stainless Steel Tubing Polished or electropolished. We also provide the pipes in different shapes such the round, rectangular or Stainless Steel 316 Square Tube. The square and 316 Stainless Steel Rectangular Tube is usually used in high pressure applications to withstand the pressure stress at change of directions. The Stainless Steel 316 Seamless Tube is more accurate in dimensions and therefore it is used in high precision applications. Our 316 Stainless Steel Exhaust Tubing is of high quality and can withstand high temperatures; it is used in exhausts, heat exchangers and super heaters. The 316 Stainless Steel Heavy Wall Tubing is used in high pressure applications such as hydraulic systems. Our SS 316 Welded Tube is easy to weld upon. We supply 316 Stainless Steel Welded Tube for affordable prices in different sizes and schedules. Please contact us for further details and pricing.
SA213 TP321 is a specification of heat exchanger tubes that are made from the 321 austenitic stainless steel.
SA213 TP321 is a specification of heat exchanger tubes that are made from the 321 austenitic stainless steel. The SA 213 specifies pipe products for heat exchangers in different material grades, both the ferritic and austenitic steels.
Sunny Steel is a supplier of all kinds of stainless steel pipes. The SA213 Tp321 Material is special in that the composition includes titanium which reduces the density of the ASME SA213 Tp321 and therefore making it lightweight.
T321 and 347 are variations of T304 and have comparable minimum tensile properties. These two grades are stabilized with additions of titanium and columbian respectively, along with proper heat treatment.
To insure good long-time strength at elevated temperatures, T321H and 347H-like 304H-were developed with higher carbon contents and specified minimum solution annealing temperatures.
Of all the stainless steels, T309 (25 chromium, 13 nickel) and T310 (25 chromium, 20 nickel) offer the maximum resistance to oxidation and corrosion. They also offer good high-temperature properties. Since these steels contain ferrite, however, they are more susceptible to sigma phase.
The ends are vertical to the longitudinal axis and are without burrs.
|26.7 - 114.3 mm
|3.2 - 12.5 mm
|4 - 13 meters
|Deburring angle, a
|30°+ 5 and 37°± 2.5
|1.6 ± 0.8 mm
The tubes with deburred ends or ends customized for welding.
We have capability and capacity to ensure boiler tube in superior condition, with advanced inspection and testing procedures, standard tests include dimensional examination, visual checking, chemical composition, mechanical properties as well as non destructive test 100% eddy current test.
Fire-tube boiler is a type of boiler in which hot gas passes from the fire through one or more pipes that pass through a sealed water container. The heat of the gas is transferred through the wall of the tube through heat conduction, heating the water and eventually generating steam. Fire tube boilers are the third of the four historical types of boilers: low-pressure tank or “haystack” boilers, flue boilers with one or two large flues, fire tube boilers and high-pressure boilers with many small tubes
Water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. The fuel is burned in the furnace to produce hot gas, which heats the water in the steam generation tube. In smaller boilers, the additional power generation tubes are separated in the furnace, while larger utility boilers rely on water injection tubes that make up the furnace wall to generate steam. High-pressure water tube boiler: The hot water then rises into the steam drum. Here, saturated steam is drawn away from the top of the drum.
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.
identification of the chemical composition of the metal used to manufacture the fitting. Uses PMI sensors, including X-ray fluorescence or optical emission spectrometry.
Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).
|Cold-finished/hard (cold-finished as-drawn)
|No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
|Cold-finished/soft (lightly cold-worked)
|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.
|After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
|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.
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.
Our packing can meet any needs of the customers.
Commonly used alloying elements and their effects are listed in the table given below.
|Effect on the Properties
|Increases Resistance to corrosion and oxidation. Increases hardenability and wear resistance. Increases high temperature strength.
|Increases hardenability. Improves toughness. Increases impact strength at low temperatures.
|Increases hardenability, high temperature hardness, and wear resistance. Enhances the effects of other alloying elements. Eliminate temper brittleness in steels. Increases high temperature strength.
|Increases hardenability. Combines with sulfur to reduce its adverse effects.
|Increases hardenability, high temperature hardness, and wear resistance. Improves fatigue resistance.
|Strongest carbide former. Added to stainless steel to prevent precipitation of chromium carbide.
|Removes oxygen in steel making. Improves toughness. Increases hardness ability
|Increases hardenability. Produces fine grain size.
|Forms nitride in nitriding steels. Produces fine grain size in casting. Removes oxygen in steel melting.
|Increases heat and wear resistance.
|Increases hardness at elevated temperatures. Refines grain size.