Designing Buildings - User contributions [en]

Plastic-coated steel pipes

2020-12-29T03:57:31Z

Datangsteelpipe: Created page with "Plastic-coated [https://www.datangsteelpipe.com/ China pipes] are in application with increasely widespread. They involve many fields, such as construction industry, electric pow..."

Plastic-coated [https://www.datangsteelpipe.com/ China pipes] are in application with increasely widespread. They involve many fields, such as construction industry, electric power industry, chemical industry and railway. Plastic-coated steel pipe is a kind of composite steel pipe, but it is more stable than simple steel pipe. And it has many advantages. Some people can't help but ask, “what is plastic-coated steel pipe?” As the name suggests, plastic-coated steel pipe is to spray plastic on the inner and outer layers of steel pipe to make the steel pipe more stable. Plastic-coated steel pipe has the strength of steel pipe and the corrosion resistance of plastic.

Therefore, plastic-coated steel pipe is more suitable for various applications and it can meet our expectations. Plastic-coated steel pipe is more and more widely used in the application process. What is plastic-coated steel pipe? We have mentioned a general concept above. The plastic-coated steel pipe is widely used in our daily life. It can be used to transport water, oil and gas. Moreover, plastic-coated steel pipe is relatively stable after spraying plastic.

The installation process of plastic-coated steel pipe for urban water pipeline, which generally includes the following steps: setting out, pipe trench excavation, pipeline installation and construction, backfilling sand, pipeline pressure test and pipeline flushing. The first is lofting, which means to determine the location of the pipeline to be buried and the route it passes through, and make actual measurement, planning and positioning on the construction site. Before the alignment, all obstacles in the pipeline trench passing through the route should be removed. And prepare the wooden pile and lime, and set out according to the route in the approval drawing. It can facilitate the excavation of the pipe trench. The excavation of pipe trench shall be carried out in accordance with the pipeline design, and the line shall be straight and level without any deflection and twists. If it is necessary to bend, the bending angle shall be generally within 20 degrees. The soil of the place is soft, retaining facilities shall be provided, and the bottom of the pipe shall be tamped. If there is water, the pipe shall be drained before laying. In the pipeline installation construction, in order to give full play to the health, environmental protection and leakage reduction performance of the plastic-coated fire pipe, the connector used for the connection with the plastic-coated fire pipe shall adopt the fully shielded double sealing pipe fitting.

When we choose plastic-coated steel pipes, the following points should be paid attention to: 
The transportation of oil, natural gas and other liquids has always been a problem worthy of attention, because there are great dangers in the transportation process. Once the leakage occurs, it will bring great loss to people and even threaten people's life safety. Therefore, the selection of plastic-coated steel pipe is to ensure the quality. So, in the selection of plastic-coated steel pipe, what problems should be paid attention to? First of all, we should pay attention to its thickness. The pipe diameter should be greater than 0.02. Because under this condition, this kind of bearing pressure is big. Even if pull hard, it will not break.

Secondly, it depends on whether its surface is smooth or not. The surface of poor quality of plastic-coated steel pipe often forms lumps, and some have small cracks. Its surface lacks luster. Once you see such steel pipe, you should know that it is not a top-grade steel pipe. Moreover, you should measure the pipe diameter from different places to see if different places are the same. Excellent steel pipe should be about every place The same, otherwise it is inferior. We should choose large manufacturers when choosing. Generally it have strict packaging. The packing is loose and often nonstandard.

[[Category:Water]]

Welding pure copper steel pipe and steel plate

2020-12-29T03:54:30Z

Datangsteelpipe: Created page with "Pure copper [https://www.datangsteelpipe.com/ China steel pipe] is a very common pipe material, because pure copper pipe is mainly made of copper pipe. So it is different from st..."

Pure copper [https://www.datangsteelpipe.com/ China steel pipe] is a very common pipe material, because pure copper pipe is mainly made of copper pipe. So it is different from stainless steel pipe in welding. Then, how to weld pure copper steel pipe and steel plate? Let's have a look!

(1) Weldability analysis of materials 
Austenitic stainless steel has certain quenching tendency and special physical properties. It is easy to produce residual stress after welding, which leads to the occurrence of hot cracks. At the same time, harmful impurities precipitate into liquid and the crack tendency increases. When austenitic stainless steel works at high or low temperature, the welded joint is easy to embrittlement.

Do you know the welding between pure copper steel pipe and steel plate?

The physical properties of pure copper determine the poor weldability. The base metal and filler metal can not be welded well after welding. It is easy to produce non melting phenomenon and has large deformation after cooling. It is easy to produce large welding stress, and the influence of impurities in pure copper may lead to hot cracks. In argon arc welding of pure copper, if a small amount of hydrogen and water vapor are added in the welding, the formation of pores should be avoided.

There are great differences in physical properties between austenitic stainless steel and pure copper. Due to the effect of welding chemical composition, welding is easy to produce defects such as hot cracks, air holes, non deposition of joints and so on. Only the correct operation method can guarantee the quality.

(2) Selection of welding parameters 
Welding wire 
Both liquid and solid nickel and copper are infinite fusion, so pure nickel is used as filler material in welding. Therefore, pure nickel wire with a diameter of 2mm is selected.

Nozzle diameter and gas flow 
The requirement of molten electrode arc welding on the protection of molten pool is very high. If the protection is not good, there will be wrinkles on the welding surface. So, the nozzle diameter is 20 mm. The argon flow rate was 35 ~ 40L / min.

Power polarity 
In order to ensure the stability of the arc, choose a good DC melting electrode welding machine. On the contrary, the welding current is 90 ~ 210A.

(3) Preparation before welding 
The distance from the overhanging end of pure copper pipe to stainless steel plate is 1mm, which is used for welding. Clean the surface of the workpiece oil, moisture and other foreign matters. When the stainless steel is scrubbed with acetone, the oil, water and other foreign matters shall be removed. Place the welded joint in the flat position.

(4) Operating point 
Use the arc starter plate to pull the arc and slowly transfer to welding until the arc is stable. 
The tilt angle of welding torch is 70 ~ 85, and the distance from nozzle to workpiece is 5 ~ 8mm. 
The action mode of the torch is that the arc moves to the pure copper pipe. The pure copper tube moves to stainless steel after melting, and the arc center keeps slightly away from the pure copper tube.

During welding, the relationship between welding speed and welding should be paid close attention to according to the variation of current. Adjust the annular moving speed of welding torch in time to ensure that the molten pool is fully protected. Please bury the crater when you close the arc. After the welding of one piece is completed, the welding stress shall be removed from the area near the welding with a wooden hammer. After welding, remove the white powder residue on the surface and clean the welding surface with copper wire brush.

[[Category:Water]]

Functions And Advantages of Thin-walled Stainless Steel Pipes

2020-12-29T03:32:42Z

Datangsteelpipe: Created page with "The stainless [https://www.datangsteelpipe.com/ China steel pipe] has high strength, strong corrosion resistance, good toughness, excellent vibration and shock resistance perform..."

The stainless [https://www.datangsteelpipe.com/ China steel pipe] has high strength, strong corrosion resistance, good toughness, excellent vibration and shock resistance performance, and it is not brittle at low temperature. In the process of water delivery, it can ensure the purity of water quality, and it is durable and renewable for use as decoration materials.

The thin-walled stainless steel pipe has the following outstanding advantages: excellent mechanical properties, excellent wear resistance, good safety and health performance, good temperature resistance, good thermal insulation performance, smooth inner wall, small water resistance; beautiful appearance, clean, fashionable, and 100% recyclable. It is conducive to saving water resources. It is wide range of use. It has long service life but in low comprehensive cost. The following is a specific introduction to the role and advantages of thin-walled stainless steel pipes. Let's have a look.

Thin-walled stainless steel pipes 
Chromium reacts with oxygen and oxidant in the thin-walled stainless steel pipes and produces passivation effect. A thin and tough dense passivation film Cr2O3 is formed on the surface of the steel pipe, which plays a protective role in corrosion resistance.

If stainless steel pipes and fittings are treated by impurity removal, pickling and passivation, the thickness of Cr2O3 generated can be increased, and the uniformity of compactness will be enhanced. After polishing and polishing of stainless steel pipes and fittings, not only surface defects can be eliminated, but also the passivation film will be more delicate and dense, so as to reduce the probability of pitting corrosion. At the same time, the inner wall of the pipe is smooth and smooth, and the friction is small, which further improves the hydraulic performance of the pipe and saves the consumption.

1. Uses and functions 
The stainless steel pipe is safe and reliable, hygienic, environmental protection, economical and applicable. The thin-walled of the pipe and the development of new reliable, simple and convenient connection method make it have more and more advantages which can not be replaced by other pipe materials. The application in engineering will be more and more, and the use will be more and more popular, and the prospect is good.

With the implementation of China's reform and opening up policy, the national economy has achieved rapid growth. Urban housing, public buildings and tourism facilities are being built in large quantities, which puts forward new requirements for hot water supply and domestic water supply. In particular, people pay more and more attention to the problem of water quality. The galvanized steel pipe, as a common pipe material, is easy to corrode. Under the influence of relevant national policies, galvanized steel pipes will gradually withdraw from the historical stage. Plastic pipes, composite pipes and copper pipes have become the common pipe materials of pipeline system. However, in many cases, the stainless steel pipe has more advantages, especially the thin-walled stainless steel pipe with wall thickness of 0.6-1.2mm has the characteristics of safety, reliability, environmental protection, economy and applicability in high-quality drinking water system, hot water system and water supply system which puts safety and sanitation in the first place. It has been proved by engineering practice at home and abroad that it is one of the best, new, energy-saving and environmental protection pipes for water supply system. It is also a kind of competitive water supply pipe material, which will play an incomparable role in improving water quality and people's living standards.

In the building water supply pipe system, as the galvanized steel pipe has ended the glorious history of one hundred years, all kinds of new plastic pipes and composite pipes have been developed rapidly. However, there are still some deficiencies in various kinds of pipes, which can not fully meet the needs of water supply pipe systems and the national requirements for drinking water and related water quality. Therefore, relevant experts predict: building water supply pipe will eventually return to the era of metal pipes. According to the application experience of foreign countries, the thin-walled stainless steel pipe is regarded as one of the best comprehensive properties among metal pipes.

Advantages of thin-walled stainless steel pipes 
Thin-walled stainless steel pipe has the following outstanding advantages: excellent mechanical properties, excellent wear resistance, good safety and health performance, good temperature resistance, good thermal insulation performance, smooth inner wall, small water resistance, beautiful appearance, clean, fashionable, 100% recyclable, conducive to saving water resources, wide range of use, long service life, low comprehensive cost, etc.

1. The thin-walled stainless steel pipe will not cause secondary pollution to the water quality and meet the requirements of the nationa

[[Category:Water]]