Cautions in use of pipe fitting bend

There are many pipe fitting bend used in the bending part of the pipeline, and the direction of the pipeline can be changed by using the pipe fitting bend. There are many kinds of Stainless Steel 90 Degree 10D 304L Large-Caliber Pipe Fitting Bend, such as 45 degree pipe fitting bend and 90 degree pipe fitting bend. The bending radius is about 1.0 times of the outside diameter of the tube, which is called short radius pipe fitting bend, and 1.5 times of the outside diameter of the tube, which is called long radius pipe fitting bend. In the pipeline system layout, it is generally appropriate to use long radius pipe fitting bend connection, short radius pipe fitting bend is usually used in the pipeline installation location is more compact occasions or in order to reduce costs.

　　When using short radius pipe fitting bend, the maximum working pressure should not exceed 0.8 times of long radius pipe fitting bend of the same specification. Oblique pipe fitting bends are usually used in large-sized pipes with low pressure, water and similar fluid medium conditions. When the angle of the single section variable direction of the oblique pipe fitting bend is greater than 45, it is better not to be used in poisonous and flammable medium pipelines, or in pipelines subject to vibration, pressure fluctuation and alternating load due to temperature change.

Properties and carbon content of carbon steel elbows

The higher the carbon content, the higher the hardness and strength, but the lower the plasticity. First, the mechanical properties depend on the carbon content in the steel, which usually does not increase a lot of alloy elements, sometimes referred to as plain carbon steel or carbon steel. Carbon steel, also known as carbon steel, refers to iron-carbon alloys with carbon content less than 2%.

　　Carbon steel can be divided into three types according to its use: carbon structural steel, carbon tool steel and free cutting structural steel. Carbon structural steel can be divided into construction structural steel and machine-made structural steel. According to carbon content, carbon steel can be divided into low carbon steel (C < 0.25%), medium carbon steel (C 0.25% - 0.6%) and high carbon steel (C > 0.6%). According to the mixture of phosphorus and sulphur, carbon steel can be divided into ordinary carbon steel (high phosphorus and sulphur content), high quality carbon steel (low phosphorus and sulphur content) and high quality steel (low phosphorus and sulphur content) usually the higher carbon content, the harder carbon steel is. The higher the strength, the higher the plasticity.

　　The use of ASTM A234 Wpb Special Carbon Steel 90 Long Redius Elbow and device use: carbon steel elbow is used for the connection of pipeline bend. Connect two pipes with the same nominal diameter to make the pipeline turn as the viewpoint. Carbon steel elbow can be said to cover the use of all walks of life throughout the country, from small families to large companies. Each carbon steel elbow has its own interests and uses.

Significant volume of sales in welded steel custom pipeline market

The surge of snails resulted in a significant volume of spot welded steel custom pipeline market transactions. The high settlement price of BS1387 Carbon Welded Steel Custom Pipeline and the price policy of not making up the difference showed a strong willingness to bid. Most other businesses had completed sales volume, so the price went up in an all-round way.

　　At present, external favorable factors dominate, downstream demand release is limited, and the trading performance of welded steel custom pipeline market is general.At the beginning of the month, the pressure of business resources slowed down, and the market's willingness to buy goods at low prices weakened.The short-term trend of billet and snail is uncertain, which has great influence on market price. Considering the above, in the off-season, the market price is still lower, but in the short term, if the billet is boosted, it may still be higher.

　　It is anticipated that the main reason for the stable operation of the welded steel custom pipeline market next week is that the market will enter the off-season and the demand is general. However, the trend of the steel billet snails can boost the mindset of the spot merchants. The market atmosphere is strong and the quotation will follow the market. In addition, at the beginning of next week, the financial pressure of the welded steel custom pipeline market will be slightly slower and the overall trend will remain stable. Fixed.

Parts of stainless steel pipe fittings out of stock

Recent environmental impact on the whole stainless steel pipe fittings market in Mengcun Yanshan, China, all types of stainless steel pipe fittings of all materials have risen by 10%-15% in a week.

　　This month's increase is even more alarming. In the 30-40% stainless steel pipe fittings market, some products have been out of stock. Today, 150lbs Threaded Stainless Steel Pipe Fittings High Press Cross of all large enterprises almost out of stock. Even the packing case has risen by 20% at a time. The original price of the wooden case of 1 meter x 1 meter is 100 and the present price is 120. Here, we remind our customers not to hesitate about the price. It is no longer a question whether they can buy high-quality products or not. In order not to affect your use, please contact us to place the order as soon as possible.

Large-caliber flange is widely used

As a sealing and fastening connector, large-caliber flange are easy to install, flexible in position and long in service life. They are widely used in large containers in aerospace, petroleum, chemical and other fields.

　　The weld of 304 Stainless Steel Socket Large-Caliber Flange should be inspected by 100% ultrasonography or radiography. There should be no cracks on the surface of large-caliber flange or other large-caliber flange connection or strength reduction defects. When the working pressure of large-caliber flange with long diameter is equal to or greater than the maximum allowable working pressure specified in the standard of 0.8 times, the butt weld of large-caliber flange and circular pipe should be inspected by 100% X-ray photograph. This method of inspection should be implemented in accordance with the provisions of JB4730. Ultrasound inspection of large-caliber flange shows that is a qualified product and it is required for radiation. If the pressure vessel pattern where the large-caliber flange is located fails to meet the above requirements for the inspection of the vessel shell, it should be carried out according to the contract or the label in the pattern.

　　Large-caliber flange can be used in different ways, which has special meaning and significance in industry and plays an important role and value in the mechanical industry.

Common faults of large-caliber flange

In the continuous production of modern industry, large-caliber flange will inevitably leak due to the influence of medium corrosion, erosion, temperature, pressure, vibration and other factors. The leakage of large-caliber flange is easily caused by the errors in the dimension of sealing surface, aging of sealing elements and improper installation and fastening.

　　If the 304 Stainless Steel Socket Large-Caliber Flange leakage problem can not be treated in time, the leakage will expand rapidly under the erosion of the medium, resulting in material loss, production environment damage, leading to shutdown of enterprises, resulting in huge economic losses. If it is toxic, harmful, flammable and explosive medium leakage, it may also cause personnel poisoning, fire and explosion and other major accidents.

　　The traditional methods to solve large-caliber flange leakage are replacing sealing elements, smearing sealant or replacing large-caliber flange and pipes. However, this method has great limitations, and some of the leakage is limited by the requirements of working environment safety, so it can not be solved on site. It is an ideal method, especially in flammable and explosive occasions, which shows its unique advantages.

　　Polymer composite technology construction process is simple, safe, and low cost, can solve most of the problems of large-caliber flange leakage for enterprises, eliminate potential safety hazards, and save more maintenance costs for enterprises.

How are cut wire shot produced?

First, scrap steel or raw material just need to detect its composition, and then add a certain proportion of alloy to melt in the furnace. Molten steel is produced by impact method, centrifugal method or atomization method. This process is also called pelletizing. After drying, the cut wire shot enter the vibrating screen. The cut wire shot are preliminarily classified into cut wire shot and steel sand. 。 After screening, the cut wire shot and steel grit are quenched again, and the tempering process is to make their hardness meet the standard requirements. Finally, further screening size and testing packaging.

　　The process of cut wire shot is the key point in the whole process. At present, the main methods are impact method, centrifugal method and atomization method.

Cast steel shots be reused?

The service life of cast steel shot is very long, because cast steel shot can be reused. At the same time, different types of cast steel shot have super long service life. The cost of using Cast Steel Shot for Shot Peening is very low, and it is very economical. Especially used in shot blasting and casting treatment, it is very useful.

　　How long is the service life of cast steel shot is the use of steel cut wire pellets, according to the different use of steel wire is divided into stainless steel shot and ordinary high-carbon steel shot and low-carbon steel shot.

　　Generally speaking, the Irving life of cast steel shot is 3000 - 3500 times, that is to say, it can be recycled so many times, in fact, there is no scrap standard, it will wear away slowly in the process of circulation, and become dust. It is very useful and can be used for surface treatment of almost any workpiece.

　　Because of its long service life, deeply loved by customers, the market is very good, and the consumption is also very large, especially in some shipyard enterprises. Generally speaking, the life of cast steel shot is 15-30% longer than that of cast steel shot, because cast steel shot has no pore and looseness, cast steel shot is mostly used for precision parts, and stainless steel shot is mostly used for stainless steel and aluminium castings, because it will not pollute the castings after shot blasting, and it is more wear-resistant. The high hardness cast steel shot is used to strengthen the blade, cylinder and connecting rod of aeroengine and diesel engine.

Advantages of cast steel grits

The cleanliness of metal surface treated by cast steel grits can reach international standards, and it has remarkable economic benefits for refining metal surface and strengthening metal structure. It is the most advanced and ideal material for cleaning, spraying, rust removal and strengthening at home and abroad. It has the characteristics of moderate hardness, strong toughness, impact resistance, continuous repeated use, long service life, good elasticity, strong adhesion, fast cleaning speed, G25 Cast Steel Grits From Reaguan consumption, no breakage, high brightness of cleaning workpiece, good technical effect, etc.

　　Many mechanical products want to have a good use effect, cast steel grit is necessary to carry out a series of treatment on the surface of equipment. There are many methods of metal surface treatment. At present, most of them are used. The best treatment effect is to use shot blasting machine to shot blasting and sandblasting metal.

　　At present, there are many kinds of abrasive products on the market, such as steel shot, cast steel grits, steel grit etc. Different abrasives are made from different raw materials. Cast steel grits products are one of the most effective abrasives.

　　Cast steel grit products have moderate hardness, strong toughness and impact resistance. They can be used repeatedly for several times. They have the characteristics of long service life, good elasticity, strong adhesion, fast cleaning speed, low sand consumption, no breakage, high brightness of cleaning workpiece and good technical effect. The products treated with cast steel grit can reach the national standard. It can be said that cast steel grit products are the most advanced and ideal material for cleaning, spraying, rust removal and strengthening at home and abroad.

Manufacturing technology of stainless steel cut wire shot

Selection of Metal Material: stainless steel cut wire shot are made of stainless steel, of course, but there are two ways to prepare stainless steel:

　　The first is to use metal or alloy raw materials for preparation, because metal or alloy raw materials are usually purchased at a lower limit, so the cost of stainless steel cut wire shot made from purchased raw materials is relatively high.

　　The second is to select the waste of stainless steel for the production of stainless steel cut wire shot. Stainless steel scraps are found everywhere, with little problem and much lower cost than the raw materials prepared by the first method. In fact, Stainless Steel Cut Wire Shot From Reaguan are used to produce stainless steel metal powder. The profit of the manufacturer is the difference between the first method and the second method of raw materials and the value-added of products. If there is no difference in the price of raw materials, there will not be much profit only depending on the value-added of products.

Is the appearance of cast steel shot brighter and better quality?

The blacker the brighter the cast steel shot, the higher the temperature of heat treatment in the production process, resulting in the reduction of carbon content in the cast steel shot, so that the hardness of the S780 Cast Steel shots becomes lower, and the cast steel shot is prone to deformation in the process of hitting.

　　So the darker the appearance, the brighter the quality of cast steel shot is not good.

　　How effective is the recycled cast steel shot used?

　　Return pellet is a new kind of cast steel shot, but the source of return cast steel shot is uneven. It is recovered from alloy cast steel shot, steel wire cut shot and other kinds of cast steel shot after hit. So the composition is not uniform and the particle size is not uniform, which seriously affects the gloss and roughness of the workpiece after hit.

Why Cast Steel Grits Treats Workpiece Surface Slowly?

The main parameters affecting cast steel grits are abrasive type, abrasive particle size, abrasive concentration, injection distance, injection angle, injection time, compressed air pressure, etc.

　　The common process parameters of cast steel grits are the acceleration effect of compressed air on jet flow (P), the type of abrasive (S), the distance (H) of the gun and the angle (θ).

　　1. The Effect of Pressure Adjustment on Surface Result

　　After setting S, H and θ, the larger the P value, the higher the velocity of jet flow, the higher the G40 Cast Steel Grit From Reaguan efficiency, the rougher the surface of the workpiece, on the contrary, the smoother the surface is.

　　2. The influence of the distance and angle of the spray gun on the surface result

　　After setting P and S values, this is the key of manual sand blasting technology. The distance between the spray gun and the workpiece is generally 50-150 mm. The farther the spray gun is from the workpiece, the lower the efficiency of jet flow and the smoother the workpiece surface are. The smaller the angle between the gun and the workpiece is, the lower the efficiency of the jet flow and the smoother the workpiece surface is.

　　3. The influence of abrasive type on surface results. Abrasives are classified into spherical and diamond abrasives according to particle state. Diamond abrasives are usually used in cast steel grits. Glass beads are spherical abrasives.

　　After setting the P, H and θ values, the surface obtained by spherical abrasive blasting is smoother, while the surface obtained by rhombic abrasive is relatively rough, and the same kind of cast steel grits is divided into roughness and fineness. In China, according to the number of screen mesh, the roughness of abrasive is generally called number number. The higher the number of screen mesh, the smaller the particle size. After setting the P, H and theta values, the higher the number of the same abrasive blasting number, the obtained. The smoother the surface is.

Points for attention in recycling cast steel grits

Cast steel grits can be reused, and proper recycling can reduce our cost rate. Cast steel grits are not only widely used but also reasonably priced, so they are loved by many manufacturers. It is used in all fields, but many manufacturers have used it once. Think that the cast steel grits has been damaged, no use value, when the garbage is thrown away, thus causing a great waste of resources, in fact, the used cast steel grits is still useful, the used cast steel grits after secondary treatment or can continue to use.

　　G40 Cast Steel Grit From Reaguan are contaminated by repeated recycling, and impurities will be mixed in the grits, which will affect the continued use of cast steel grits. At this time, cast steel grits need to be self-cleaning. The impurities in cast steel grits can be divided into solid impurities and soluble salts. Different treatment methods should be adopted for the two kinds of objects.

　　1. Solid impurities are cleaned up by clear air. In the recycling cycle, cast steel grits can be recovered by an automatic sand absorption separator, which can remove most of the bulk impurities and more than one third of the dust, and remove the solid impurities in the process of entering the sand storage bucket through the abrasive screening machine.

　　2. Soluble salts in cast steel grits can be removed by periodic water cleaning, and can be used alternately between cast steel grits for different purposes in recycling.

　　In order to recycle cast steel grits, we need to clean them to a certain extent. Only in this way can we make better use of cast steel grits.

Method of spiral steel pipe cutting off

At present, plasma cutting is a common way of pipe closure for spiral steel pipe manufacturers. When cutting, a large number of metal vapors, ozone and nitrogen oxide fumes will occur, which will seriously pollute the surrounding environment. The main way to deal with the problem of smoke and dust is how to inhale all the plasma smoke and dust into the dedusting equipment, so as to prevent air pollution.

　　However, the difficulty of dust removal in plasma cutting of API 5L X52 Psl-2 Welded Spiral Steel Pipe is as follows:

　　1. When plasma gun is cut, air is blown out to two counter-targets at the same time, so that smoke and dust come out from both ends of the spiral steel pipe. Spiral steel pipe is difficult to recover the smoke and dust from the suction port installed on one target of the spiral steel pipe.

　　2. The cold air outside the suction inlet enters the suction inlet from outside the mechanical leisure time and the air volume is very large, which makes the total amount of smoke and cold air in the steel pipe larger than the useful air volume inhaled by the dust collector, thus the complete suction of cutting smoke and dust becomes impossible.

　　3. Because of the distance between the cutting parts and the dust removal inlet, it is difficult for the wind force arriving at the suction inlet to smoke and dust.

Specific Elimination Method of Galvanized Pipe

1. The banded structure caused by component segregation, i.e. when the galvanized pipe contains harmful impurities such as phosphorus and is calendered, the impurities elongate along the calendering direction.

　　2. The banded structure caused by improper hot working temperature, i.e. when the stop forging temperature is in the two-phase zone, ferrite precipitates from austenite along the direction of galvanized pipe. The undissolved austenite is cut into bands, and the banded austenite is transformed into banded pearlite.

　　3. Galvanized pipe is difficult to eliminate the banded structure caused by segregation by heat treatment. Normally normalizing can alleviate the segregation to a certain extent.

　　The reason for the formation of banded structure is the segregation of alloy elements ASTM A106 Cold Rolled Seamless Steel Galvanized Pipe, especially the segregation of sulfur and phosphorus and various non-metallic inclusions, such as MnS and silicate inclusions, which are easy to form banded structure. Dendrite segregation during solidification of steel can not be eliminated during subsequent pressure processing, and often retains the banded structure. In addition, improper hot-binding and forging processes, especially without repeated forging and reversal forging in different directions, will also preserve the ribbon structure of raw materials.

The possibility of oil casing falling is very high

The northern part of the domestic mining market was slightly downgraded and the turnover was cold. At present, the ratio of domestic ore allocation in steel mills is gradually decreasing, which makes the production capacity of domestic oil casing continue to decline, and the pessimism of manufacturers spreads. Import mining market weakness consolidation. The trend of oil casing derivatives market is weak and the overall turnover is not good.

　　Influenced by seasonal factors, the downstream terminal market has gradually stagnated, the purchase of raw materials has obviously contracted, and the oil casing enterprises have insufficient confidence in the future market, so the atmosphere of waiting and seeing is quite strong. The short-term iron ore market is expected to continue to decline. On the market side, the recent decline has been weak, although the margin is small, but the overall market has been in a weak position, for the finished seamless pipe manufacturers, API 5CT J55 Oil Casing is also a blow. In addition, many manufacturers intend to drastically reduce inventory, most believe that next year, seamless pipe is facing shuffling pattern, when the funds are insufficient, there may be bankruptcy risk. Short-term market prices are expected to be weak.

　　On the whole, the market is quiet today, but this situation will not last long. With the strength of finished products and futures turning weaker, the shortfall of scrap steel market is also gathering. Later demand situation will ultimately determine the fate of scrap steel market. Resource constraints will not last long, and the possibility of oil casing falling in the later period is very large. Oil casing is suggested that businesses operate cautiously.

Why can't carbon steel pipe fitting elbow touch water?

Carbon dioxide is a kind of impurity in water, which usually exists in a free state. A large number of bicarbonates in water exist in the free state of carbon dioxide when the pH is low, so the problem of A234 WPB 90 Degree Long Radius Carbon Steel Pipe Fitting Elbow. The more carbon dioxide in water, the more H + formed, the lower the pH value of water, the more acid corrosive water produced, which destroyed the protective film formed on the surface of carbon steel and caused the corrosion of carbon steel.

　　If carbon steel pipe fitting elbow is introduced into desalted water, the conductivity of water will increase and the corrosiveness will increase. Therefore, the desalination tank should have measures to prevent the atmospheric carbon dioxide from dissolving into the water tank, such as using N2 or other inert gas to protect the top space of the water tank, so as to prevent carbon dioxide from polluting the water quality of pure water.

　　Carbon steel pipe fitting elbow is a common compound in the air. The chemical formula of carbon and oxygen is carbon dioxide. A carbon dioxide molecule consists of two oxygen atoms and one carbon atom through covalent bonds. It is a colorless odorless gas at room temperature. Its density is higher than that of air. It can dissolve in water and react with water to form carbonic acid. It does not support combustion. Carbon steel pipe fitting elbow is commonly referred to as dry ice after compression. Carbon dioxide is not considered to be the main source of aggravating the greenhouse effect.

Scope of working characteristics of pipe fitting tee

　This basic structure entity model of pipe fitting tee is an overall description of electronic measuring instruments. In the main instruments and equipment, the situation will be very different.

　　For example, the data signal collection, signal analysis and data signal transformation of pipe fitting tee are all carried out by the same resistance network power supply circuit, while the current large digital storage oscilloscope only consists of several power supply circuits. The characteristic of DN450 Carbon steel Seamless BW Pipe Fitting Tee is to qualitatively analyze the quantity of the characteristics of the instrument and equipment by the scope of standard value and deviation, which can also be called the performance index. The working characteristics of pipe fitting tees are mainly divided into the working characteristics of electrical equipment and the common working characteristics.

　　Under the condition of standard uniform motion in work, the reliability of pipe fitting tee is called the reliability of instrument and equipment, whose label value or supply and demand balance value will not change during the required time. Reliability is immediately time-dependent. Resolution is the ability that the measuring instrument will test to be the least transformed by accurate measurements. Usually, the resolution of pipe fitting tee is one big number of the reading device, and the resolution of the analog instrument is half of the minimum scale of the reading device.

Pipe fittings reducer heat treatment technology

　In the process of shrinkage or expansion deformation pressing of pipe fittings reducer, cold pressing or hot pressing should be adopted according to the different material and diameter variation of the tube. Usually, cold pressing should be adopted as far as possible, but in the case of severe hardening caused by multiple diameter variation, hot pressing should be used for the material with thicker wall thickness. Diameter expansion is a tube with a diameter smaller than pipe fittings reducer's large end. The blank is formed by inner die along the inner diameter of the tube blank. The expanding process mainly solves the problem that ASME B16.9 Stainless Steel Pipe Fittings Reducer with larger diameter is not easy to be formed by shrinking. Sometimes, according to the forming requirements of materials and products, the methods of expanding and shrinking are combined.

　　Hot-pressed tees are suitable for materials of low carbon steel, alloy steel and stainless steel. Especially for tees with large diameter and thick wall, this forming process is usually adopted. Besides using steel pipe as raw material to produce pipe fittings reducer, the hot-pressed tees have wide adaptability to materials. The sheet metal can also be produced by the stamping process. The shape of the stamping die used for drawing refers to the dimension design of the inner surface of pipe fittings reducer, and the blanked sheet metal can be stamped and drawn by the stamping die.

Development Trend of Carbon Steel Pipe Fitting Cap in the Future

After the development in recent years, the quality of head products has been greatly improved, but due to the weak technical foundation, the concept of quality is not yet fully established, the quality of A234 Wpb Carbon Steel Pipe Fitting Cap is unstable, especially the internal quality is difficult to guarantee. Some enterprises of pipe fitting caps also have poor production environment, serious soot pollution and high labor intensity, affecting the image of enterprises.

　　Although the headline industry has begun to enter the road of specialization, most of the headline professional enterprises belong to private enterprises, and the reform is relatively lagging behind. The imperfect market environment and inadequate supervision and management have led to a large number of enterprises of pipe fitting caps often resorting to improper means of competition to wage price wars. This competition makes it difficult to guarantee quality, which not only damages users, but also sacrifices the interests of manufacturers and pipe fitting caps, and disrupts the market order.

　　In addition, the backward management of enterprises, the imperfect quality system, the imperfect production and operation network and the low level of marketization are all the problems that need to be solved urgently in the current headline industry.

How to store pipe fitting bend?

1. Long-term storage of pipe fitting bend should be inspected regularly. The exposed surface should be kept clean, dirt removed, neatly stored in indoor ventilated and dry places, and stacking or open storage are strictly prohibited. Often keep pipe fitting bend dry and ventilated, keepers clean and tidy, according to the accurate storage method.

　　2. When installing, the pipe fitting bend can be directly installed on the pipeline in connection mode and installed in accordance with the position used. Generally, Seamless Buttwelding A234 Wp91 Pipe Fitting Bend can be installed in any position of the pipeline, but need to be easy to operate the inspection, pay attention to the cut-off pipe fitting bend media flow should be upward flow under the longitudinal valve disc, pipe fitting bend can only be installed horizontally. When installing the pipe fitting bend, we should pay attention to the sealing, prevent leakage and affect the normal operation of the pipeline.

　　3. When using pipe fitting bend ball valves, globe valves and gate valves, they should only be fully opened or closed, and not be allowed to adjust flow rate, so as to avoid erosion of sealing surface and accelerate wear. There is an inverted sealing device in the gate valve and the upper thread globe valve. When the handwheel is screwed to the top position, the leakage of the medium from the packing can be prevented.

The role of resources allocation in blind flange market is becoming more and more obvious

For iron and steel industry, the new normal means that the era of high growth and high profit driven by high-speed demand growth will never return; steel demand growth slowed down significantly and entered the arc-top platform area; market supply exceeds demand, the role of resource allocation in ASTM A182 150LBS Dn100 Blind Flange market is increasingly obvious, and the price of products and raw materials is restrained; enterprise competition is from the same direction. With the qualitative change to differentiation, enterprises with poor competitiveness and backward production capacity will be eliminated. Whether the new normal is fully understood and whether the flange adjustment is in place in time will directly determine the future and destiny of the enterprise.

　　Demand in the downstream is lagging behind, production of blind flanges is only increasing, and the general wait-and-see situation of iron and steel traders makes the market depressed both inside and outside, exports are decreasing, production is rising, and contradictions are still intensifying. On the export side, the trade barriers of other countries to China's steel products are still increasing, trade frictions are becoming more and more intensive, and the recovery of European economies is difficult, etc. All of these have brought adverse factors to China's steel exports. In a word, the road of China's export is not optimistic in the future, and the reduction of steel exports. It is bound to reduce the confidence of domestic businessmen, optimistic values or will drop sharply, the upward movement of flange is also extremely unfavorable.

Maintenance of weld neck flange

For workpieces with complex shape or sharp change of cross section and larger effective thickness, preheating should be carried out.

　　The methods of preheating are: 800?C for one time, 500-550 and 850 for two times. The speed of temperature rise for one time should be limited.

　　1. Heating:

　　Workpieces, castings and welds with grooves and no through holes, and ASTM A105 Dn150 Class 150 RF Weld Neck Flange processed and formed, are generally not suitable for heating in salt bath furnaces.

　　Workpiece heating should have sufficient holding time, depending on the effective thickness and conditional thickness of the workpiece.

　　2. Cleaning:

　　Workpieces and fixtures should be cleaned of foreign substances weld neck flange, residual salt and paint before heat treatment.

　　The fixture used for the first time in vacuum furnace should be degassed and purified in advance at the required vacuum degree of the workpiece.

　　3. Furnace loading:

　　Weld neck flange that are easily deformed during heat treatment should be heated on special fixtures.

　　Workpiece should be placed in the effective heating zone

How do socket flanges divide pressure levels

Socket flanges are used in different places, so the pressure level is different to a certain extent. For example, large stainless steel DIN Class300 Forged Carbon Steel Socket Flanges are mainly used in high temperature pipelines in chemical engineering, so the material pressure performance of socket flange is very high.

　　Therefore, customers often require forging socket flanges, because the material after forging increases the density of the organization, but also enhance its pressure bearing capacity.

　　In domestic and international standards, the pressure resistance of large stainless steel socket flanges has clear grade requirements. Large stainless steel socket flanges are generally divided into: PN25, PN6, PN10, PN16, PN25, PN40 and so on. The most commonly used are PN10 and PN16.

　　For example, the design pressure of socket flanges of internal pressure vessel with safety valve should be determined according to the opening pressure of safety valve. The design pressure is equal to or slightly greater than the opening pressure of the safety valve, while the opening pressure of the safety valve is 1.05-1.1 times of the working pressure.

　　Given that the working pressure is 0.8 MPa, the opening pressure of the safety valve can be 0.88 MPa, so the design pressure can be 0.9 MPa. In this way, it is reasonable to choose the material 1C4 of vessel socket flanges with the maximum allowable working pressure of 0.9 MPa at 50 degrees Celsius.

What are the differences between cold forging and hot forging of slip-on flanges?

Cold forging of slip-on flanges is a process of forging at low temperature, and the size of slip-on flanges changes little. When forged below 700 C, less oxide scales are formed and no decarbonization occurs on the surface. Therefore, as long as the deformation energy is within the range of forming energy, cold forging can easily obtain good dimensional accuracy and surface finish. As long as temperature and lubrication cooling are well controlled, warm forging below 700 C can also achieve good accuracy. Cold die forging, cold extrusion, cold upsetting and other plastic processing. Cold forging is a forming process below the recrystallization temperature of the material and a forging process below the recovery temperature. Cold forging has good surface quality and high dimensional accuracy, which can replace some cutting processes. Cold forging can strengthen metal and improve the strength of DIN2502 RF Pn16 Stainless Steel Slip-on Flange.

　　The development of cold forging technology is mainly to develop high value-added products and reduce production costs. At the same time, slip-on flanges is constantly infiltrating into or replacing cutting, powder metallurgy, casting, hot forging, sheet metal forming process and other fields. It can also be combined with these processes to form a composite process.

　　Hot forging of slip-on flanges is: in hot forging, large slip-on flanges with complex shapes can be forged because the deformation energy and resistance are very small. To obtain slip-on flanges with high dimensional accuracy, hot forging can be used in the temperature range of 900-1000 C. In addition, attention should be paid to improving the working environment of hot forging. The life of forging die is shorter than that of forging in other temperature domains, but it has higher freedom and lower cost. The main purpose of hot forging slip-on flanges is to reduce the deformation resistance of metal, thus reducing the forging pressure required for bad material deformation and greatly reducing the tonnage of forging equipment; changing the as-cast structure of steel ingot used for slip-on flanges, recrystallizing in the process of hot forging, the coarse as-cast structure becomes a new structure with fine grains, and reducing the defects of as-cast structure and improving the mechanical properties of steel.