Galvanized Steel Pipe vs Stainless Steel Pipe
Stainless Steel Pipe is the most durable
Galvanized Pipe is good for 10 or 8 years
Stainless Steel Pipe lasts a lifetime
Price wise?
Stainless steel pipe is 10 times more expensive than galvanized pipe
Galvanized pipe price has the advantage of cheap
Stainless steel pipe once and for all Save the usual processing costs
Galvanized pipe introduction
Galvanized pipe, also known as galvanized steel pipe, divided into two kinds of hot-dip galvanizing and electro-galvanizing, hot-dip galvanizing galvanized coating is thick, with an even layer of plating, strong adhesion, and the advantages of long service life. Electro-galvanized low cost, the surface is not very smooth, its own corrosion resistance is much worse than hot galvanized pipe.
Nominal wall thickness mm 2.0 2.5 2.8 3.2 3.5 3.8 4.0 4.5
Coefficient c 1.064 1.051 1.045 1.040 1.036 1.034 1.032 1.028
Steel grades: Q215A; Q215B; Q235A; Q235B
Test pressure value/Mpa: D10.2-168.3mm is 3Mpa; D177.8-323.9mm is 5Mpa.
Theoretical weight table and formula of galvanized pipe
Theoretical weight formula of galvanized pipe: (diameter - wall thickness) x wall thickness x 0.02466*1.0599 = weight per meter (kg/) (m)
Main use
Commonly referred to as galvanized pipe is now mainly used to transport gas, heating. Galvanized pipe as a water pipe, after a few years of use, the pipe produces a large amount of rust scale, outflow of yellow water not only contaminated sanitary ware, but also entrapped in the unsmooth inner wall of the breeding bacteria; rust corrosion caused by the water is too high in the content of heavy metals, a serious danger to human health. Sixty, seventy years, the international developed countries began to develop new types of pipe, and gradually banned galvanized pipe. China's Ministry of Construction and other four ministries and commissions have also issued a clear from two hundred and ten years from the ban on galvanized pipes.
Introduction of stainless steel pipe
Stainless steel pipe is a kind of economic section steel, is an important product in the iron and steel industry, can be widely
Stainless steel pipe
Used in life decoration and industry, the market is used by many people to make the staircase handrails, window guards, railings, furniture and so on. Commonly available 201 and 304 two kinds of materials.
Accounting for about 8% a 16% of the total amount of all steel, it has an extremely wide range of applications in the national economy. Because the steel pipe has a hollow section, and therefore most suitable for liquid, gas and solid transportation pipeline; at the same time with the same weight of round steel, steel pipe section coefficient is large, bending and torsion strength, so it also becomes a variety of mechanical and architectural structure of the important material. Structures and components made of stainless steel tube, in the case of equal weight, has a larger section modulus than solid parts. Therefore, the stainless steel tube itself is a kind of metal-saving economic section steel, it is an important part of efficient steel, especially in the oil drilling, smelting and conveying and other industries in greater demand, followed by geological drilling, chemical industry, construction industry, machinery industry, aircraft and automobile manufacturing, as well as boilers, medical equipment, furniture and bicycle manufacturing and other aspects of a large number of various kinds of steel tubes are also needed. With the development of atomic energy, rockets, missiles and space industry and other new technologies, stainless steel tube in the defense industry, science and technology and economic construction in the status of the more important.
Stainless steel pipe is safe, reliable, hygienic and environmentally friendly, economically applicable, thin-walled pipeline and the development of new reliable, simple and convenient connection method is successful, so that it has more other tubes irreplaceable advantages, the application of the project will be more and more, the use of more and more popular, the prospect of a good www.bxgb304.com. ? As stainless steel has been equipped with many of the ideal properties required for construction materials, it can be said to be unique in the metal, and its development is still continuing. Improvements are always being made to existing types in order to make stainless steel perform better in traditional applications, and new stainless steels are being developed to meet the stringent requirements of advanced architectural applications. As a result of increasing production efficiencies and improving quality, stainless steel has become one of the most cost-effective materials chosen by architects.
Stainless steel combines performance, appearance and usage characteristics, so stainless steel will remain one of the world's best building materials.
With the implementation of China's reform and opening-up policy, the national economy has gained rapid growth, and a large number of town houses, public **** buildings and tourist facilities have been built, which has put forward new requirements for hot water supply and domestic water supply. Especially water quality, people are paying more and more attention to the problem, the requirements also continue to improve. Galvanized steel pipe this commonly used pipe because of its easy corrosive, under the influence of relevant national policies, will gradually withdraw from the stage of history, plastic pipe, composite pipe and copper pipe into the piping system commonly used pipe. But in many cases, stainless steel pipe is more superior, especially the wall thickness of only 0.6 ~ 1.2mm thin-walled stainless steel pipe in the high-quality drinking water system, hot water system and will be safe, hygiene in the first place to the water supply system, with safe, reliable, hygiene and environmental protection, affordable and so on. Has been proved by domestic and foreign engineering practice is the best comprehensive performance of the water supply system, one of the new, energy-saving and environmentally friendly pipe, but also a very competitive water supply pipe material, will improve water quality, improve people's standard of living to play an unparalleled role.
In the building water supply pipe system, as galvanized steel pipe has ended a century of glorious history, a variety of new plastic pipe and composite pipe has been the rapid development of the pipe, but a variety of pipe is still varying degrees of some of the shortcomings, far from fully adapted to the needs of the water supply pipeline system and the country's drinking water and the quality of the water requirements. Therefore, the experts predicted: building water supply pipe material will eventually return to the era of metal pipe. According to foreign application experience, in the metal pipe identified as thin-walled stainless steel pipe as one of the best overall performance of the pipe.
Promotion
Thin-walled stainless steel pipe, the domestic production and use in the late 1990s, is today's pipe field emerging newborns, has been applied to a large number of building water supply and drinking water pipeline.
Thin-walled stainless steel tube is durable, has been recognized by the engineering community, and the relevant parties are working to reduce the wall thickness, reduce the price, in order to facilitate further promotion. Especially small diameter stainless steel pipe, the price is not high, so supporting the connection method, the reliability of the fittings and price is the main factor determining its development. Domestic developers in Sichuan, Guangdong, Zhejiang, Jiangsu and other places have developed their own connection technology and fittings, is very promising pipe. The Ministry of Construction and relevant departments also attach great importance to this new type of pipe, according to the Chinese technology market management and promotion center, national science and city word [2001] No. 71 document, on the promotion and application of "high diameter and wall ratio of high-precision stainless steel medium- and high-pressure water supply pipe and supporting pipe fittings and special technology," the notice was informed that the thin-walled stainless steel pipe this technology and product Promote the application of modern architecture in China to improve the grade, improve and safeguard the quality of water supply is of great significance.
At the same time, the Ministry of Construction attaches great importance to the promotion and application of thin-walled stainless steel pipe. Thin-walled stainless steel water pipe" industry standards have been released in 2001. Related pipeline engineering technical regulations and installation atlas, the Ministry of Construction has issued a document, is responsible for the preparation of Tongji University. Currently, Sichuan, Guangdong, Zhejiang, Jiangsu and other places have specialized manufacturers of thin-walled stainless steel pipe, the product has become mature, and therefore, the time to promote the application has arrived.
Domestic prospects
①Demand for building water supply piping
According to the "Construction Business" Ninth Five-Year Plan and 2010 Visionary Goals Outline "calculated that between 2001 and 2010, the annual demand for pipe for 50 to 60 million km, of which the residential building areas Hot and cold water pipe demand for 400,000km. it is believed that the development of stainless steel water pipe, to improve the grade of modern urban buildings, is of great significance.
②Pipeline drinking water development is rapid
With the development of the national economy, pipeline drinking water in the domestic Beijing, Shenzhen, Shanghai, Chongqing and other cities are developing rapidly, economically developed medium-sized cities are also actively planning to catch up. In the direct drinking water, stainless steel pipe system is undoubtedly second to none. The current domestic upscale hotels, public **** places have been configured or in the configuration of direct drinking water pipeline.
③ Domestic substitution of imports has a broad future
In order to promote stainless steel pipe, China since the 1990s from the reduction of wall thickness, reduce the cost of starting to solve the "high diameter and wall ratio of high-precision" thin-walled stainless steel pipe technology, so that stainless steel pipe to promote the application of the development of a very fast. A pipe to be able to promote the application of a comprehensive, indispensable localization. When the domestic manufacturers have a part of the production and further development of thin-walled stainless steel pipe and pipe fittings capacity.
Connection
The stainless steel pipe connection methods are diverse, common types of fittings are compression, compression, live, propulsion, push-threaded, socket welded, live flange connection, welded and welded with the traditional connection combined with a derivative series of connection methods. These connections, according to its principle of different, its scope of application is also different, but most of them are easy to install, firm and reliable. Connection of the sealing ring or gasket material, most of the selection of national standards in line with the requirements of the silicone rubber, nitrile rubber and EPDM rubber, etc., eliminating the user's worries.
Compression connection steps
1, broken pipe: cut off the pipe according to the required length, broken pipe, do not force too much to prevent the pipe out of round.
2, deburring: pipe cut off, the burr should be removed cleanly, so as not to cut the seal.
3, line marking: in order to make the pipe completely inserted into the pipe fittings socket, must be marked at the end of the pipe insertion length of the line.
4, assembly: the sealing ring should be correctly installed in the U-shaped groove of the fittings, the pipe will be inserted into the fittings socket, waiting for crimping.
5, crimping: crimping, pipe fittings raised parts placed in the mold concave groove, jaws and pipe axis to maintain vertical.
6, check: crimping is completed, the use of special gauges to check the crimping size.
Stainless steel corrosion resistance reasons
All metals react with atmospheric oxygen to form an oxide film on the surface. Unfortunately, the iron oxide that forms on plain carbon steel continues to oxidize, allowing rust to expand and eventually form holes. The surface of carbon steel can be secured by plating using paint or oxidation-resistant metals (e.g., zinc, nickel, and chromium), but, as is well known, this protection is only a film. If the protective layer is broken, the steel underneath begins to rust.
The corrosion resistance of stainless steel depends on chromium, but because chromium is one of the components of steel, the methods of protection vary.
At chromium additions up to 10.5%, the steel's atmospheric corrosion resistance increases significantly, but at higher chromium levels, although the corrosion resistance can still be improved, but not significantly. The reason for this is that when steel is alloyed with chromium, the type of surface oxide is changed to a surface oxide similar to that formed on pure chromium metal. This tightly adhering chromium-rich oxide protects the surface from further oxidation. This oxide layer is so thin that the natural luster of the steel surface can be seen through it, giving stainless steel its unique surface. Moreover, if the surface layer is damaged, the exposed steel surface will react with the atmosphere for self-repair and re-form this "passivation film" to continue to play a protective role.
Therefore, all stainless steels have a **** the same characteristics, that is, the chromium content are more than 10.5%.
There are usually only six grades of steel that are relevant to building construction applications. They all contain 17 to 22 percent chromium, and the better grades also contain nickel. The addition of molybdenum further improves atmospheric corrosion resistance, especially to chloride-containing atmospheres.
Stainless steel resistance to atmospheric corrosion
Experience has shown that the degree of atmospheric corrosion varies from region to region. For illustrative purposes, it is recommended that geographic areas be divided into four categories, namely: rural, urban, industrial and coastal areas.
The countryside is an essentially unpolluted area. This zone has a low population density and has only non-polluting industries.
Urban is a typical residential, commercial and light industrial area with light pollution such as traffic pollution.
Industrial zones are areas where heavy industry causes air pollution. Pollution may be due to gases formed by fuel oil, such as sulfur and nitrogen oxides, or other gases released from chemical plants or processing plants. Suspended particles in the air, like dust from steel production or deposits of iron oxides can also increase corrosion.
Coastal areas are usually defined as areas within a mile of the sea. However, the oceanic atmosphere can spread deep inland, and even more so on islands, where the prevailing winds come from the ocean and the climate is harsh. Such are the climatic conditions in Britain, for example, that the whole country falls within the coastal zone. If the winds are interspersed with marine mist, especially if there is a build-up of salt deposits due to evaporation, and if there is little rainfall and infrequent washing away by rain, the conditions in the coastal region are even more unfavorable. If there is also industrial pollution, it is even more corrosive.
Research work carried out in the United States, the United Kingdom, France, Italy, Sweden and Australia has determined the effect of these regions on the resistance of various stainless steels to atmospheric corrosion. This is briefly described in NiIDI's Architect's Notebook, which contains tables to help designers select the most cost-effective stainless steel for various zones.
When making a selection, it is important to determine whether there are any local factors that affect the environment of the site where it will be used. For example, stainless steel used underneath a factory chimney, near an air-conditioning exhaust baffle or near a scrap yard will have unusual conditions.
Maintenance and Cleaning of Stainless Steel
Like any other material exposed to the atmosphere, stainless steel can get dirty. Future lectures will analyze the design factors that affect maintenance and cleaning costs. However, there is also a correlation between rainfall, manual washing, and already dirty surfaces.
The effect of rain washout was determined by placing identical slats directly in the atmosphere and by placing them in a covered area. The effect of manual washing was determined by manually scrubbing the right side of each slat with a sponge moistened with soapy water at six-month intervals. It was found that the removal of dust and silt from the surface by rainwater flushing and manual scrubbing had a favorable effect on the surface condition as compared to the slats placed in the shedded area and in the area that was not rinsed. And it was also found that the condition of the surface finish also had an effect, with slats with smooth surfaces having better results than slats with rough surfaces.
The interval between washes is therefore influenced by a number of factors, the main one being the aesthetic standard required. While many stainless steel curtain walls are simply washed when the glass is cleaned, stainless steel used for exteriors is generally washed twice a year.
Typical Uses of Stainless Steel
Most uses require that the original appearance of the building be maintained over time. In determining the type of stainless steel to be selected, the main considerations are the aesthetic standard required, the corrosive nature of the atmosphere at the location and the cleaning regime to be adopted.
However, other applications are increasingly just looking for structural integrity or impermeability. Examples include roofs and side walls of industrial buildings. In these applications, the owner's cost of construction may be more important than aesthetics, and a surface that is not very clean is fine.
Using 430 stainless steel in dry indoor environments works quite well. However, to maintain its appearance outdoors in the countryside and cities, it needs to be cleaned frequently. In heavily polluted industrial and coastal areas, the surface can get very dirty and even rusty. However, to obtain the aesthetic effect in outdoor environment, nickel-containing stainless steel is required. Therefore, 304 stainless steel is widely used for curtain walls, side walls, roofs and other architectural purposes, but in highly aggressive industrial or marine atmospheres, 316 stainless steel is preferred.
The superiority of using stainless steel in structural applications is well recognized. Several design guidelines include 304 and 316 stainless steels. Because the "duplex" stainless steel 2205 has good atmospheric corrosion resistance and high tensile and elastic strength in one, so the European guidelines also include this steel.
Stainless steel product shapes
In fact, stainless steel is manufactured in all standard metal shapes and sizes, but also in many specialized shapes. The most commonly used products are made from sheet and strip, but also medium and thick plates are used to produce special products, for example, hot rolled structural sections and extruded structural sections. And there are also round, oval, square, rectangular and hexagonal welded or seamless steel tubes and other forms of products, including profiles, bars, wire and castings.
Surface Condition
As will be discussed later, a number of different commercial surface finishes have been developed to meet the aesthetic requirements of architects. For example, surfaces can be highly reflective or non-glossy; they can be glossy, polished or embossed; they can be tinted, colored, plated or etched with patterns on the stainless steel surface to meet the various requirements of designers for appearance.
Maintaining the surface condition is easy. Dirt can be removed with only occasional rinsing. Due to good corrosion resistance, it is also easy to remove writing contamination or similar other surface contamination from the surface.