The essence of stainless steel is steel that is not easy to rust. It is a type of steel. The main components of steel are alloys of iron, carbon and a small amount of other elements. Chromium (Cr), nickel (Ni) and manganese are added during the smelting process. (Mn), silicon (Si), titanium (Ti), molybdenum (Mo) and other alloying elements, thereby improving the performance of the steel, making the steel corrosion-resistant, that is, it is not easy to rust. Due to the different characteristics of the alloy elements added, and the different addition amounts of different varieties, there are different grades and different properties of stainless steel. In order to be distinguished, there are different grades of stainless steel, such as 201 stainless steel, 304 stainless steel, 316 stainless steel, etc. . So what are the characteristics of these alloy elements? Please continue to look down 1. Carbon (C): All steels have this element. It is the most important hardening element and enhances the hardness of the steel. 2. Chromium (Cr): Improve the wear resistance and hardness of steel. Its performance is corrosion resistance. If the steel has 13% chromium content, it can be simply said that the steel is stainless steel. 3. Nickel (Ni): Maintain strength, increase corrosion resistance and toughness. 4. Manganese (Mn): Contributes to the formation of the texture structure of stainless steel, increases the firmness, strength, and wear resistance of stainless steel, and deoxidizes the interior of the steel during processing. 5. Silicon (Si): Maintain and enhance the strength of steel during the production process. 6. Titanium (Ti): It mainly plays a role of quenching and tempering. For example, when the carbon content of stainless steel is high, carbides are easily formed during welding, which reduces the corrosion resistance of stainless steel. In this case, generally A small amount of titanium is added. 7. Molybdenum (Mo): Plays the role of chloride corrosion resistance in stainless steel. This element is basically contained in high-grade stainless steel. Generally speaking, steel is an alloy of iron and carbon. The other components are just to make steel have different properties, improve the performance of steel, and make steel have corrosion resistance. This is what we often call stainless steel.
1. Weld the flange to the pipe and cool it to ambient temperature before installing the valve onto the flange. Otherwise the high temperatures generated by the weld can affect the performance of the resilient seat. 2. The edge of the welded flange must be machined to a smooth surface to avoid damage to the resilient seat during valve installation. The surface of the flange must be completely free from damage and deformation, remove all dirt and foreign matter, and avoid liquid leakage at the valve and flange interface. 3. Clean the flange and the inner cavity of the pipe to completely remove the splashes, peeling scale and other foreign matter left by the welding. 4. When installing pipes between valves, precisely aligning the center of the upper and lower water pipes is critical for trouble-free operation. The inaccurate center point must be avoided. 5. When installing the valve, set the positioning bolts under the pipe to the same height to support, and adjust the distance between the flanges until the sides of the valve body are about 6-10 mm apart. Remember that the valve can only be opened from the closed position to a 10° position. 6. Insert the two bolts into the lower guide rod of the valve and carefully install them so that the flange surface does not damage the resilient seat. 7. Then place the other two bolts into the guide rod above the valve to ensure accurate center position between the pipe and the valve. 8. Open the valve three times to check whether there is poor contact between the valve plate and the flange or not. 9. Remove the positioning bolts and place all bolts around the body for alternate diagonal tightening until the flange touches the valve body. Please refer to the table below for the recommended torque values. 10. Provide a support for the valve when installing the actuator to avoid distortion of the valve neck and reduce friction between the valve and the pipe. 11. Do not step on the valve neck or valve handwheel. 12. Do not reverse the installation of valves of the DN350 or larger. 13. Do not install the butterfly valve directly on the check valve or pump, as this may cause damage when contacting the valve plate. 14. Do not install the valve on the downstream side of the elbow and the reducer, or calibrate the valve as the flow rate changes. In this case, it is recommended to install the valve at a distance of approximately 10 times the nominal diameter of the valve. 15. Installation of the valve requires consideration of which valve plate will experience the effects of flow rate and pressure during liquid transport.
A ductile iron pipe is made of a kind of cast iron, carbon and silicon alloy, is an iron ore stone blast furnace smelting product. According to the different forms of carbon in pig iron, it can be divided into steel-making pig iron, cast iron and ductile iron and so on. Ductile iron is a kind of high-strength cast iron material developed in the 1950s, and its comprehensive performance is close to steel. Based on its excellent performance, ductile iron has been used to cast some of the high-strength, high-toughness, wear-resistant parts. Ductile iron has rapidly developed into a very extensive cast iron material after gray iron. The so-called "iron substituting steel", mainly refers to ductile iron. Graphite in a ductile iron pipe is in the form of spheroidal graphite. The general graphite size grade is 6-7. In terms of quality, the spheroidization grade of cast iron pipes is required to be 1-3, and the spheroidization rate is 80%, so the mechanical properties of the material itself have been improved. The microstructure of ductile iron pipe after annealing is ferrite with a small amount of pearlite, and the mechanical properties are better. A ductile iron pipe is also called centrifugal ductile iron pipe, whose fittings are magnesium or rare earth magnesium combined with gold pellets before pouring into molten iron, so that the stress concentration of graphite ball is reduced. A ductile iron pipe has advantages such as excellent anti-corrosion performance, ductility, good sealing effect, easy installation. Ductile Iron pipe is mainly used for water, gas, oil in municipal, industrial and mining enterprises projects. A ductile Iron pipe is the first choice for water supply pipes, which is cost-effective. Compared with the PE pipe, from the installation time, the ductile iron pipe is simpler and quicker than PE pipe in installation, and the pressure inside and outside is better after installation. In terms of the airtightness and anti-corrosion performance, the ductile iron pipe has better tightness after installation, and also through a variety of anti-corrosion means to improve the performance. From the hydraulic performance, because the ductile iron pipe specification generally refers to the inner diameter, and PE pipe specification generally refers to the outside diameter, with the same specifications, the ductile iron pipe can achieve greater runoff. From the comprehensive installation and maintenance cost, the ductile iron pipe is superiorly cost-effective.
Teel pipes can be categorized into welded and seamless types. The following introduces several common steel pipe production methods. Seamless pipe Seamless pipe is produced without a seam or weld in the circumference. Seamless pipe is produced by a variety of methods. To put it in its most simple terms, seamless pipe is produced by piercing a solid billet of deoxidized and conditioned steel, which has been properly prepared and heated to the proper temperature. It is then processed through a series of mills where the pipe is finished to its prescribed dimensions. Seamless pipes over 14-inch are usually rotary rolled from 14-inch seamless shells which expand the diameter and reduce the wall thickness to the approximate dimensions required. Small sizes of seamless pipe are generally obtained through the use of a stretch reduced mill. In this process, the outside diameter and the wall thickness of the pipe is reduced through a series of rolls. Seamless pipe goes through various finishing operations including straightening, inspection, testing, and end finishing. Seamless pipe is widely used in construction, oil refining, chemical and petro-chemical industries. Continuous welded pipe Continuous welded pipe poduction begins with coiled skelp of the required width and thickness for the size and weight of pipe to be made. Successive coils of steel are welded end to end to form an endless ribbon of steel. The coiled steel is fed into a roll leveler and then into a gas fired furnace where it is heated to the required temperature for forming and welding. The forming rolls at the exit end of the furnace shape the heated skelp into an oval. The edges of the skelp are then firmly pressed together by welding rolls to obtain a forged weld. The heat of the skelp, combined with the pressure exerted by the rolls form the weld. No metal is added in the operation. The final rolls on the mill reduce the diameter and wall thickness to bring the pipe to its finished dimensions. The pipe is then cooled, descaled, straightened, inspected, tested hydrostatically, coated as required and end finished. Continuous welded pipe is commonly used for the conveyance of water, air, gas, steam, for sprinkling systems, water wells, fencing, and a multitude of structural applications. Double submerged arc welded pipe Double submerged arc welded pipe (DSAW) derives its name from the welding process wherein the welding arc is submerged in flux while the welding takes place. Both inside and outside welds are required and are usually accomplished in separate processes. These separate welds consume a portion of the other resulting in a single high quality weld nugget. DSAW pipe is produced in sizes from 18 inch through 72 inch and wall thicknesses from 0.250 inch through 1.5 inch. Two different processes are used to manufacture DSAW pipe: the pyramid rolls method, and the U-O-E method. The difference in the processes is found only in the method of forming the cylinder. In the pyramid rolls process the cylinder is formed between 3 rolls arranged in a pyramidal fashion. As the name implies, the U-O-E method uses a "U" press, and "0" press for forming. Other parts of the process such as finishing and inspection are similar. Both processes use flat steel plate as the raw material. DSAW pipe is normally produced in double random lengths with square or beveled end for welding. It is usually furnished barely but varnish is also offered. A wide range of external coatings and internal linings are availa ble with DSAW pipe. DSAW pipe is used in high pressure gas and oil transmission lines (both onshore and offshore), structural members and pipe piles. Spiral welded pipe Spiral welded pipe, as the name implies, is a steel pipe which has a seam running its entire length in a spiral form. In the past, due to the method of manufacture, spiral welded pipe was relegated to low pressure and structural applications. With the development of the submerged arc welding process, the production of large hot rolled coils of sufficient width and the development of dependable non-destructive testing methods, it is now possible to produce spiral weld pipe for high pressure service.
Tianzhu Special Steel Co., Ltd.
Address:Jingshi International Office Building,Dongting Mid-Road ,Xishan District,Wuxi City, Jiangsu Province, China.
Jingshi International Office Building,Dongting Mid-Road ,Xishan District,Wuxi City, Jiangsu Province, China.
Tel:86 18651560206
Whatsapp:+86 18651560206
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