What are the technical requirements for elbows in engineering projects?

/in /by

What are the technical requirements for elbows in engineering projects?

1. Since most of the pipe fittings are used for welding, in order to improve the welding quality, the ends are beveled, with a certain angle and a certain side. This requirement is also strict, how thick the side, how much angle and deviation The scope is stipulated. The surface quality and mechanical properties are basically the same as the pipe. For the convenience of welding, the steel grade of the pipe fitting and the pipe being connected is the same.

2. All pipe fittings must undergo surface treatment, and the oxide scale on the inner and outer surfaces shall be sprayed off by shot blasting, and then coated with anticorrosive paint.

3. For the packaging requirements of small pipe fittings, a wooden box is required, about 1 cubic meter, and the number of elbows in this box cannot exceed one ton. Sets are allowed, that is, large sets and small sets, but the total weight generally cannot exceed 1 ton. . For large-diameter elbows, single packaging is required, such as 24″ must be individually packaged. The other is the packaging mark, which must indicate the size, steel number, batch number, manufacturer’s trademark, etc.

Decho is a professional supplier on elbow fitting products . If you need any material for your project , pls contact us by email [email protected]

Features and structure shape of butt welding flange

/in /by

Butt welding flange is a kind of pipe fittings, which refers to the flange with neck and the transition of round pipe and butt welding with the pipe.

Butt welding flanges are not easy to deform, have good sealing, and are widely used. They have corresponding rigidity and elasticity requirements and reasonable butt welding thinning transition. The distance between the welding port and the joint surface is large, and the joint surface is protected from welding temperature deformation. The horn-shaped body structure is suitable for pipelines with large fluctuations in pressure or temperature or high temperature, high pressure and low temperature pipelines. It is generally used for the connection of pipelines and valves with a PN greater than 2.5MPa; it is also used for transporting expensive, flammable and explosive On the pipeline of the medium.

Production material

WCB (carbon steel), LCB (low temperature carbon steel), LC3 (3.5% nickel steel), WC5 (1.25% chromium 0.5% molybdenum steel), WC9 (2.25% chromium), C5 (5% chromium% molybdenum), C12 ( 9% chromium 1% molybdenum), CA6NM (4 (12% chromium steel), CA15(4) (12% chromium), CF8M (316 stainless steel), CF8C (347 stainless steel), CF8 (304 stainless steel), CF3 (304L stainless steel) ), CF3M (316L stainless steel), CN7M (alloy steel), M35-1 (Monel), N7M (Haast Nickel Alloy B), CW6M (Hasta Nickel Alloy C), CY40 (Inconel)

Connection form : One-sided welding, double-sided nut connection.
Product features : Beautiful appearance, smooth surface, acid and alkali resistance, anti-corrosion, and strong texture performance.
Production process : The material is cut in the sub-oxygen furnace, the whole is forged or the finished product is forged and cut.
Processing method: High-precision CNC lathe turning, CNC radial drilling and drilling.

Product parameter
(1) The diameter of the center circle of the bolt hole: 50mm—-2130mm
(2) Bolt hole diameter: 11mm-30mm
(3) Flange thickness: 12mm-58mm
(4) Tube outer diameter: A(17.2-2032MM) B(14-2020MM)
(5) Flange inner diameter: A (18-2036MM) B (15-2024MM)
(6) Theoretical weight of flange: 0.36kg–234.6kg (DN1800)

Decho is a professional supplier on flanges , if you need any for your project , pls contact us by email [email protected]

What are the connection methods of wear-resistant ceramic pipes?

/in /by

Wear-resistant ceramic pipes are widely used in the industrial field, especially in high-wear working environments, such as power plants, cement plants, mines and other enterprises. Wear-resistant ceramic pipes reflect the incomparable advantages of other products.

Wear-resistant ceramic pipe connection method

1. Fixed flange connection

Fixed flange connection means that the flange is directly welded to the pipeline and connected by bolts. However, once the flange is welded, the bolt hole cannot be adjusted, so some drawings will mark the angle of the bolt hole.

2. Live flange connection

The live flange welding head is turned up, so that the bolt hole can be adjusted, and there is no need to correct the position of the bolt hole when connecting with another flange.

3. Welding method

Glue is needed to fix wear-resistant ceramics, but the glue cannot withstand the high temperature during welding. Because the temperature of steel pipe welding is very high, it can be hundreds of degrees in an instant, and the heat transfer speed of steel is very fast, so the welding place needs to keep a certain distance from the ceramic. Leave a distance of at least 2 cm, which is generally called a 2 cm welding end.

Precautions for installation of wear-resistant ceramic pipes

1. In the process of handling and installation, wear-resistant ceramic pipes should be handled with care to avoid serious collisions. In particular, avoid direct contact with or impact on end ceramics by metal equipment.
2. When the wear-resistant ceramic pipe needs to be cut during the installation process, it can be cut with silicon carbide grinding wheel or plasma cutting machine, and gas cutting is not allowed.
3. When the wear-resistant ceramic pipeline is installed, the center line of the pipeline and the pipeline should be aligned to ensure that the two ends are connected accurately, and the amount of misalignment of the two ends should be controlled within 1.0mm.
4. When the flexible pipe socket is used to connect and install the pipeline, the double-end insertion length of the flexible pipe sleeve is adjusted symmetrically. Since the coefficient of thermal expansion of the wear-resistant ceramic pipe is 1/2 of that of the steel pipe, the expansion gap can be reduced by 3-5mm.
5. When using flange connection, the flange end surface must be flush with the wear-resistant ceramic pipe end surface to ensure the reliability of the connection method.

Decho is a professional supplier on wear resistant ceramic pipes , if you need any , pls contact us by email : [email protected]

What is a bimetal composite wear-resistant pipe?

/in /by

What is a bimetal composite wear-resistant pipe?

The outer wall of the bimetal composite wear-resistant pipe is made of ordinary seamless steel pipe, which is compounded by a high-chromium cast steel lining through a centrifugal forming process. The outer wall of the elbow is made of shrimp elbows, and the inner layer is made of high-chromium cast steel, which not only has the wear resistance of high-alloy cast steel, but also can withstand pressure, and has higher mechanical properties.

Bimetal wear-resistant pipeline characteristics:

1. Good wear resistance 　 the hardness of super-hard wear-resistant alloy HRC≥46, with good wear resistance and thermal stability.
2. Excellent impact resistance, metal bonding performance, thermal shock resistance 　KMTBCr28 bimetal composite wear-resistant elbow, the bonding surface of the two metals is completely metallurgical, and it is safe and reliable to use. The thermal expansion coefficients of the two are equivalent, and there will be no expansion and contraction. The outer wall of the elbow is made of steel pipe, and the inner lining is made of super-hard wear-resistant alloy. This product not only has the wear-resistant and corrosion-resistant characteristics of high-alloy products, but also has higher mechanical properties and higher impact resistance.
3. Good heat resistance and corrosion resistance. The matrix of super hard alloy material has strong heat resistance and corrosion resistance, and can show good corrosion resistance and wear resistance under high temperature or corrosive environment. Under the interaction of wet state, corrosive media and particle erosion, it is more appropriate to use super-hard wear-resistant alloys used in as-cast state; and under dry conditions where abrasive wear is the main failure mode, use a A super-hard and wear-resistant alloy material that can obtain a martensite matrix through heat treatment.
4. Low composite cost and good quality 　 The wear-resistant tube is manufactured using international advanced lost foam casting technology, with high yield, good product compactness, uniform thickness and stable quality.
5. Convenient transportation, installation and use 　 The bimetal composite wear-resistant pipe can be connected by flange, quick joint, direct welding and other methods. Moreover, due to the high impact resistance of the composite pipe, when a partial blockage occurs during the maintenance of the pipeline system, it can be knocked, hammered, or cut, removed, welded, installed and repaired at will.

 

Decho is a professional supplier of bimetal composite wear-resistant pipe. If you need any for your project, pls contact us by email [email protected]

Welding process of bimetal composite pipe

/in /by

The outer wall of the bimetal wear-resistant composite pipe is made of ordinary seamless steel pipe, which is compounded by a high chromium cast steel lining through a centrifugal forming process. The outer wall of the elbow is made of shrimp elbows, and the inner layer is made of high-chromium cast steel, which not only has the wear resistance of high-alloy cast steel, but also can withstand pressure, and has higher mechanical properties.

In the bimetal wear-resistant composite pipe lining alloy material, the hardness and wear resistance are high-chromium wear-resistant white cast iron and high-quality alloy wear-resistant cast steel (collectively referred to as super hard wear-resistant alloy). The hard phase of high chromium cast iron is M7C3 type carbide, its hardness reaches HV1500～1800, so it has good wear resistance, and because the structure of this Ka type carbide is rod-like, it has high toughness . On the basis of traditional ingredients, rare metals and boron carbide hardening agents are added, which greatly increases the hardness and fatigue resistance of traditional products and makes their wear resistance better than other products.

This process is suitable for welding requirements of bimetal composite pipe castings:
1. When installing the bimetal composite pipe, the pipe and the center line of the pipe should be aligned to ensure that the two ends of the pipe are connected accurately. Due to the high hardness of the high chromium alloy lining, only ordinary steel pipes on the outer wall can be welded, and penetration must be performed. When cutting on site, a plasma cutting machine must be selected for on-site cutting according to the thickness of the composite pipe.
2. Select J507 ordinary welding rod with a diameter of φ4.0mm.
3. Generally, DC electric welding machine is used for welding, and AC electric welding machine can also be used for welding.
4. After the bevel welding at both ends is completed, use the reinforcement hoop in the middle of the weld and continue welding with the outer wall of the composite pipe to ensure the firmness of the weld.
5. Avoid welding under 0℃ or low temperature and humidity.
6. Spot welding, symmetrical welding, and then integral welding should be adopted for welding parts to avoid stress concentration casting cracking.
7. In order to ensure the welding quality of the bimetal composite pipe, the welding surface should be cleaned to avoid defects such as oil stains and slag inclusions.

Decho is a professional supplier on bimetal composite pipe, if you need any , pls contact us by email [email protected]

What is the difference between PTFE lined pipe and rubber lined pipe?

/in /by

What is the difference between PTFE lined pipe and rubber lined pipe?

Tetrafluoro is a polymer of tetrafluoroethylen, short for PTFE. Polytetrafluoroethylene (Poly tetra fluoroethylene, abbreviated as PTFE), is generally called “non-stick coating” or “easy to clean material”. This material is resistant to acids, alkalis, and various organic solvents, and is almost insoluble in all solvents. At the same time, PTFE has the characteristics of high temperature resistance, and its friction coefficient is extremely low, so it can be used for lubrication and become an ideal coating for easy cleaning of the inner layer of water pipes.

The tetrafluoroethylene lining uses fluorine’s corrosion resistance, high temperature resistance, strong acid and alkali resistance, excellent adhesion, long service life, and strong penetration resistance. The entire spraying of PTFE is a high-tech work, and its process What are the processes?
1. Special spraying process. Before spraying, the surface needs to be roughened by sandblasting and sprayed with a special primer.
2. The fluoroplastic powder is then charged by a high-voltage electrostatic device, and is uniformly adsorbed on the surface of the workpiece under the action of an electric field.
3. After high temperature baking, the clinker particles will melt into a dense protective layer firmly attached to the surface of the workpiece. For example, a 1mm thick coating film also needs to be sprayed and baked repeatedly 5-6 times, usually the thickest Can be sprayed to 2mm.

Lining tetrafluoroethylene is currently a widely used technology. It makes full use of fluorine’s corrosion resistance, high purity cleanliness, non-stickiness, non-wetting, self-lubricating, abrasion resistance, high and low temperature resistance, and insulation During the construction process, the voltage and current are constantly adjusted to the ideal state to achieve the coating effect.

Rubber lining, also known as rubber lining, English translation is rubber lining. It is to stick the processed whole rubber sheet on the metal surface with adhesive to separate the corrosive medium from the metal matrix for the purpose of protection. The rubber used for lining includes natural rubber and synthetic rubber. The rubber used for chemical equipment lining is mostly natural rubber. The main component of natural rubber is a cis-polymer of isoprene, which is vulcanized by vulcanization, and the vulcanized rubber has certain heat resistance and mechanical strength. It can be divided into soft rubber, semi-hard rubber and hard rubber. Hard rubber has good corrosion resistance, aging resistance and strong adhesion to metal; soft rubber has good cold resistance, heat resistance and impact resistance, and has a certain degree of flexibility; while semi-hard rubber is between between the two. Except for strong oxidants and certain solvents, hard rubber can withstand most of the corrosion of inorganic acids, organic acids, alkalis, salts, and alcohols. Therefore, hard rubber lining is used as the main non-metallic anti-corrosion material. Vulcanized rubber can be divided into pre-vulcanized rubber, atmospheric hot water vulcanized rubber and natural vulcanized rubber. Pre-vulcanized rubber should be used in larger pickling equipment.

The above is the difference between the two. Decho can supply you pipeline either with PTFE linning or rubber lining . If you need any for your project , pls feel free to contact us by email [email protected]

PTFE pipeline is the first choice for industrial sewage lining

/in /by

Steel-lined PTFE pipe is a kind of green plastic pipe with the most anti-corrosion, wear-resisting, energy saving and environmental protection. Its wide application has accelerated the process of new environmental protection roads in mines to a certain extent. It not only realizes the low-carbon and environmental protection of mine operation, but also saves cost and manpower and material resources for mining investment enterprises, makes mine transportation safer and more reliable, and increases transportation speed.

Now, a new type of plastic pipe that meets the needs of society and has been applied-steel lined PTFE pipe. Most industrial sewage requires extremely corrosion-resistant pipelines, because industrial sewage contains corrosive media, and these corrosive media must be toxic and harmful chemicals. To transport and process these toxic and hazardous chemicals, green anticorrosive steel-lined PTFE pipelines are the best choice.

The tetrafluoroethylene pipe fittings are made of ordinary carbon steel pipe as the matrix, and are lined with thermoplastic polytetrafluoroethylene (Teflon or PTFE, F4) plastic with excellent chemical stability, processed by a specific process. It not only has the mechanical properties of steel pipes, but also has the characteristics of high corrosion resistance of tetrafluoroplastics, anti-scaling, and not easy to grow microorganisms. It is an ideal pipeline for transporting strong acids, strong alkalis, industrial salts and strong corrosive gases.

High chemical stability:
It can withstand all strong acids, including aqua regia, hydrofluoric acid, concentrated hydrochloric acid, nitric acid, fuming sulfuric acid, organic acids, etc., strong alkalis, strong oxidants, reducing agents and various organic solvents. Very suitable for feeding high-purity chemicals. The wide temperature range is -30℃~-250℃. The low friction coefficient is generally only 0.04, which is a very excellent self-lubricating material, and the friction coefficient does not change with temperature changes. Excellent anti-adhesion: the inner wall of the tube is not easy to adhere to colloids and chemicals. Excellent aging resistance, can be used outdoors for a long time. Excellent electrical insulation performance, PTFE is a highly non-polar material with good dielectric properties, extremely high electrical resistance, and a dielectric constant of about 2.0, which is the smallest among all electrical insulation materials. High flexibility and resistance to bending. Part of the tube has high transparency, and the internal fluid condition can be easily observed.

Product advantages:
1) High temperature resistance-working temperature up to 250℃
2) Low temperature resistance-has good mechanical toughness, even if the temperature drops to -196 ℃, it can maintain 5% elongation.
3) Corrosion resistance-It is inert to most chemicals and solvents, and can withstand strong acids and alkalis, water and various organic solvents.
4) Weather resistance-has the best aging life among plastics
5) High lubrication-is the smallest friction coefficient among solid materials.
6) No adhesion-it is the smallest surface tension among solid materials and does not adhere to any substance.
7) Non-toxicity|——non-toxicity to organisms

This product is widely used in electric power, chemical, petrochemical, environmental protection and other industries. Decho is a professional supplier on PTFE pipes, if you need any for your project, pls feel free to contact us by email [email protected]

Process and application of self-propagating ceramic composite pipe

/in /by

1. The principle of self-propagating ceramic composite pipe:

The ceramic composite pipe is manufactured by self-propagating high temperature synthesis + centrifugal casting, that is, the seamless steel pipe is placed in the tube mold of the centrifuge, and the thermite (a mixture of iron oxide powder and aluminum powder) is added to the steel pipe, and the centrifuge tube mold After the rotation reaches a certain speed, the thermite is ignited by electricity, the combustion wave spreads rapidly, and the explosion takes shape. The following violent chemical reactions occur during spreading:
• 2A1+Fe2O3=Al2O3+2Fe+836KJ
• 3Fe3O4+8Al=4AL2O3+9Fe+3256KJ

After the reaction, the products a-Al2O3, ß-Al2O3 and iron, and emit a lot of heat at the same time. Due to the rapid reaction, only a few seconds, the molten reactant is quickly separated according to the specific gravity under the action of centrifugal force. The specific gravity of iron (7.85g/cm3) is twice that of Al2O3 (3.95 g/cm3), and the heavier iron Throwing to the inner wall of the steel pipe by centrifugal force, the lighter Al2O3 is distributed in the inner layer of iron; due to the rapid heat absorption and heat transfer of the steel pipe, Al2O3 and Fe quickly reach the freezing point and solidify in layers; the final ceramic steel pipe is formed separately from the inside to the outside It is a corundum porcelain layer, an iron-based transition layer, and an external steel pipe layer. High-temperature molten iron and Al2O3 liquid contact with the inner wall of the steel pipe to make the inner wall of the steel pipe in a semi-soluble state, so that the iron layer and the steel pipe form a metallurgical bond, and the iron layer and the corundum ceramic layer also form a firm bond.

2. Features of self-propagating ceramic composite pipe

• The composite pipe made by the high-temperature centrifugal synthesis method is a dense corundum ceramic that is fired at a high temperature of 2200 degrees. The dense corundum ceramic and steel pipe are firmly combined by the transition layer.

• Process: Ceramic powder + iron oxide powder + magnesium oxide powder are mixed in proportion (the main component is iron oxide, black), seal both ends of the pipe, add the powder, rotate the pipe, electronic ignition, and sinter on the inner wall of the pipe by centrifugal method. The effect of pipes below ø100 is better. The pipe is generally black.

• Features: high strength, good toughness, impact resistance, good weldability, which solves the contradiction between weldability and wear resistance.

• Wear resistance and high temperature resistance

3. Spontaneous combustion application field

 

Self-spreading ceramic composite pipes can be used in high temperature areas, with simple production, convenient construction, and low cost. The diameter of the pipe is not more than 600mm, and the wear resistance is lower than that of ceramic patch pipes.

Disadvantages: Due to the short reaction time, the low-temperature phase alumina and molten iron are not completely separated, resulting in the ceramic layer is not dense, the particles are loose, the micro-cracks are many, the quality is brittle, it is easy to partially fall off and fail, and it cannot be compensated after fall off. It can only be made into a straight tube. If it is made into an elbow, the straight pipe must be divided into several sections for welding. The formed elbow is not streamlined, which hinders material transportation and reduces the output force of the equipment

Decho is a professional supplier on self-propagating ceramic composite pipe. If you need any , pls feel free to contact us by email [email protected]

Process and application of integral calcined ceramic composite pipe

/in /by

The whole calcined ceramic composite pipe is composed of seamless steel pipe, calcined ceramic pipe and filler

Integral calcined ceramic pipeline process

Desulfurization ceramic wear-resistant pipes are assembled by firing ceramic pipe fittings as a whole, and pouring the shaped ceramic pipes inside the steel pipe with special fillers. The alumina content of the ceramic pipe fittings lining the desulfurization wear-resistant pipeline is not less than 95%. 200T dry pressing, sintering temperature is as high as 1670℃. Its advantages are: smooth inner wall, good sealing, and very good wear resistance and corrosion resistance.

Production Process
According to the mold, the ceramic powder is sintered into a ceramic pipe, and then combined with the steel pipe. The outer wall of the ceramic pipe and the inner wall of the steel pipe are assembled by pouring a special filler (cement or epoxy resin) inside the steel pipe, and then isostatically pressing. During the sintering process, the furnace cools quickly, cracks easily, and the process is more complicated. The pipe is generally white.

Application of wear-resistant pipe
• Power plant boiler pulverization system pipes, including pulverized powder conveying pipes, coarse and fine powder separator pipes, coal drop pipes, primary air pipes, secondary air pipes, tertiary pipes and burner pipes of the combustion system, and the discharge of the ash and slag discharge system Slag pipeline, powder return pipeline, dry ash transportation pipeline;
• Steel plant raw material conveying pipes, receiving pipes, dust removal pipes, ash discharge pipes, ash falling pipes, batching mixing pipes, mill outlet pipes, coal-fired pipes, pulverized coal pipes, separator pipes, burner square pipes, etc. ；
• Cement plant separator outlet pipes, separator inlet pipes, dust collection pipes, vertical mill outlet pipes, circulating air pipes, coal mill high temperature fan air pipes, discharge pipes and other worn bends.

Decho is a professional supplier on integral calcined ceramic composite pipe. If you need any for your project , pls feel free to contact us by email [email protected]

Ceramic patch wear-resistant pipe and fittings

/in /by

Ceramic composite steel pipe: straight pipe, elbow pipe, reducer pipe, tee, pipeline automatic compensator and special-shaped pipe of various specifications between φ50-φ1400

What is a ceramic-lined steel pipe?

Ceramic lined steel pipe is a kind of composite pipe that combines ceramic and metal organic. Ceramic steel pipe combines the advantages of high alumina hardness, good chemical inertness and steel, and has excellent wear resistance, corrosion resistance, heat resistance and heat resistance Impact and resistance to mechanical impact, used for power plant pulverized coal, slag, mine powder, tailings, backfill, coal in coal mines, beneficiation plants, coke particles in coking plants, and sintering plant materials. The service life is 15 longer than ordinary steel pipes. It can also be used for the transportation of molten aluminum and corrosive media. The thermite-centrifugal method prepares the ceramic-lined steel pipe using the high temperature generated by the reaction itself to melt the reaction products and separate them under the action of centrifugal force to form a steel pipe lined with alumina ceramics, with low energy consumption and fewer processes.

Performance of ceramic lined steel pipe:

1. Wear resistance: The Al2O3 content in the inner ceramic layer of the ceramic composite steel pipe is greater than 90%, the hardness is HV1000-1600, and the density is 3.8-3.97g/cm3, so it has extremely high wear resistance, and its wear resistance is higher than that after quenching The medium carbon steel is ten times higher than the tungsten carbide.
2. Corrosion resistance Ceramics are neutral materials with stable chemical properties, excellent corrosion resistance and acid resistance, resistance to various inorganic acids, organic acids, organic solvents, etc., and its corrosion resistance is more than ten times that of stainless steel.
3. Heat resistance The ceramic layer is dense corundum with a linear expansion coefficient of 6-8×10-6/℃. Excellent heat resistance, can withstand temperatures above 2000℃, and can work for a long time in the range of -50℃～900℃.
4. Mechanical properties: It has excellent mechanical properties. Its crush strength is 300-600MPa, compressive shear strength is 20-30MPa, and the mechanical impact test has no obvious cracks under 50t energy impact for 15 times.
5. Easy to weld: The ceramic-lined composite steel pipe can be connected by welding the outer steel pipe.
6. Convenient transportation and installation: Compared with steel pipes, wear-resistant alloy cast pipes, cast iron pipes and cast stone pipes, ceramic-lined composite steel pipes are relatively light in weight and easy to transport and install. Ceramic lining composite steel

Ceramic lined steel pipe connection method

The pipe can be connected by welding, flange, flexible quick joint, etc., which is very convenient for installation.

Application of ceramic lined steel pipe

Ceramic-lined steel pipes can be used for a variety of pipes in thermal power, steel, non-ferrous metals, mining, coal, chemical, petrochemical and other industries due to their excellent performance:
1. Pipelines requiring high wear resistance: coal and ash (slag) transportation pipelines in thermal power plants, tailings and concentrate transportation pipelines in concentrators, port slurry and sediment transportation pipelines, pulverized coal slurry transportation pipelines, etc.
2. Various pipelines requiring high corrosion resistance.
3. Molten aluminum liquid transportation pipeline.
4. Various channels requiring high wear resistance, high corrosion resistance and high temperature resistance. Economic benefits: Compared with wear-resistant alloy cast iron pipes and cast stone pipes, ceramic-lined steel pipes are used as wear-resistant pipes. Due to the light weight per unit length, the support and hanger costs, handling costs and installation costs are reduced, which greatly reduces the project cost .

Decho is a professional supplier on Ceramic patch wear-resistant pipe and fittings. If you need any for your project , pls contact us by email [email protected]