The defect of buried pipeline

Corrosion of buried pipelines in the urban sewage treatment project is mainly soil erosion, which is characterized by scattered piping, soil conditions are very complex, so the corrosion mechanism is very complex.

Soil erosion and soil in the salt, water, oxygen and the electrochemical corrosion of coating steel pipe composition, microbial erosion. As the urban underground electrical facilities, cable is more dense, stray current corrosion is more serious, even through the pipeline near the plant may be acid or alkaline media of chemical corrosion.

Buried pipelines often pass through the city roads, buildings, rivers, etc., under pressure complicated. In addition, the pipeline may be buried by rock backfill sand during the collision and extrusion damage.

The event of buried pipeline inspection and repair corrosion damage is not easy to make corrosion worse. Often result in the repair environmental damage. Because of this, and the corrosion of coating steel pipe design life of the general requirements in 20 ~ 30a above.

More information,pls visit:Hunan Great Steel Pipe Co.,ltd

Shapes and Standard of Structural Steel Pipe &Tube

Pls check below pictures to know the Shape and Standard of structural steel pipe.

ASTM A500, A53 ,A106, A252 Structural Steel Pipe

ASTM A500, A53 ,A106, A252 Structural Steel Pipe, is a welded steel tube with a variety of sizes to meet the structural piping requirements for applications the water, petroleum, oil & gas and other industries. Carbon steel pipe can be structural in nature or used in fluid, gas, oil transmission. Carbon steel piping specifications were in A500, A53, A106 and A252.The grade indicates the testing methods required for a given application.

It has an internal weld seam that is measured in nominal size unlike DOM or Welded Round Tube. A500 Steel Pipe is a economical structural grade pipe with a smooth bare finish that has slighter higher mechanical properties than standard pipe. Our  A53 sch 80 Steel Pipe is a tested pipe that can be used for structural or pressure applications and may have a black coated finish. It is critical that structural grades of carbon steel pipe not be used for pressure or fluid applications.

•          Specifications: ASTM A500 Grade B; A106; A252, ASTM A53 Gr B, Type E, Tested
•          Applications: frames, roll cages, truck racks, trailers, railings, etc.
•          Workability: Easy to Weld, Cut, Form and Machine
•          Mechanical Properties:                
  o   A500 - Tensile = 58,000, Yield = 46,000+/- ;
  o   A53 - Tensile = 60,000, Yield = 30,000+/-
  o   A252 GRADE 1 –Tensile=50,000, Yield= 30,000+/-
  o   A252 GRADE 2 –Tensile=  60,000, Yield= 35,000+/-
  o   A252 GRADE 3 –Tensile=  66,000, Yield= 45,000+/-
  o   A106 Grade A-Tensile=48,000,Yield=30,000+/-
  o   A106 Grade B-Tensile=60,000,Yield=35,000+/-
  o   A106 Grade C-Tensile=70,000,yield=40,000+/- 

A500 steel pipes Characteristics and Applications:

A500 steel pipes can be subjected to most of the usual fabricating operations. Ductility is good. It bends well, flattens, cuts, punches, flares and flanges easily, and can be welded by the commonly-used techniques and practices.Common uses for ASTM A500 pipe include hand rails, posts, storage racks, displays, furniture, Structural applications, Bollards, Micro-piling.

A53 steel pipes Characteristics and Applications:

Designed for coiling, bending and flanging, A53 carbon steel pipe is suitable for welding. The grades denote certain chemical and mechanical properties and should be noted in selection.A53 pipe is intended for mechanical and pressure applications and is also acceptable for ordinary uses in steam, water, gas and air lines, Low pressure systems, Structural applications,  Mechanical components, Bollards, Casing

ASTM A53 PIPE TYPES

The following types & grades of A53 pipe are covered within this specification:

• Type F – Furnace-butt-welded, continuous welded Grade A
• Type E- Electric-resistance-welded, Grades A and B
• Type S- Seamless, Grades A and B

ASTM A106 steel pipes Characteristics and Applications:

A106 pipe is always produced by the seamless method and can be bent, coiled and flanged. In sizes less than 2" is it usually produced as a cold drawn product. 2" and up are usually hot finished.This pipe is always produced by the seamless method and is intended for use in high temperature applications, Pressure systems, Mechanical components, Structural applications, Spreader bars.

A252 steel pipes Characteristics and Applications:

A252 pipe is a welded and seamless structural steel pipe for piling.The steel cylinder acts as a permanent load carrying member or as a shell to form cast–in–place concrete piles. Structural applications, Spuds,Dolphins. 

Fusion Bond Epoxy Coating

FBE coating is an industry standard, environmentally-safe thermoset polymer coating which is used as corrosion protection for pipe.

Fusion bond epoxy coating, also known as powder coating or FBE coating steel pipe, is an epoxy-based powder coating widely used to protect steel pipe used in pipeline construction, piping connections and valves from corrosion.  They come under the category of 'protective coatings' in paints and coating nomenclature. 

Resin cross-linking, the hardener components and the application method used in the dry powder fusion bond epoxy coating do not react at normal storage conditions. At typical coating application temperatures, usually in the range of 180° C to 250° C (360° F to 480° F), the contents of the powder melt and transform to a liquid form. The liquid FBE film wets and flows onto the steel surface to which it is applied and soon becomes a solid coating by chemical cross-linking.  This process is assisted by heat and is known as “fusion bonding”. The chemical cross-linking reaction taking place in this case is irreversible. Once the curing takes place, the coating cannot be returned to its original form by any means. Application of further heating will not melt the coating and thus it is known as a thermoset coating.

During the FBE process:

• the pipe surface is cleaned and heated
• epoxy powder is electrostatically applied onto the pipe
• the powder melts onto the pipe and quickly dries into a uniform and controlled thickness 

Hunan great steel pipe co.,ltd has multiple FBE coating steel pipe facilitie. The facilities are capable of handling 2-inch to 60-inch diameter pipes up to 80 feet in length. 

Liquid Epoxy Coatings

Hunan great steel pipe co.,ltd utilizes innovative plural component liquid spray equipment to apply liquid epoxy coatings to pipe, valves, fittings and bends.

• Standard service temperature resistance (up to 185°F)
• Service temperatures up to 250°F (121°C)
• High-build (up to 50 mils in one coat)
• Excellent adhesion (compliments FBE coated pipe)
• High abrasion resistance for Drilling applications
• Safe and environmentally friendly
• Does not shield Cathodic Protection
• Sacrificial coating for directional drill and road bore pipe

If you would like to know more about coating steel pipe,pls contact us.

Despite Climate Change Vow, China Pushes to Dig More Coal

JINCHENG, China — America’s uncertain stance toward global warming under the coming administration of Donald J. Trump has given China a leading role in the fight against climate change. It has called on the United States to recognize established science and to work with other countries to reduce dependence on dirty fuels like coal and oil.

But there is a problem: Even as it does so, China is scrambling to mine and burn more coal.

A lack of stockpiles and worries about electricity blackouts are spurring Chinese officials to reverse curbs that once helped reduce coal and structural steel pipe production. Mines are reopening. Miners are being lured back with fatter paychecks.

China’s response to coal scarcity shows how hard it will be to wean the country off coal. That makes it harder for China and the world to meet emissions targets, as Chinese coal is the world’s largest single source of carbon emissions from human activities.

Among China watchers, the turnabout also has contributed to questions about the fate of China’s current crop of economic planners.

Here in Jincheng, a smoggy city in China’s coal country, the about-face has led to a steady hum of activity. On a recent afternoon, other trains stopped to make way for two electric locomotives, their horns blowing, pulling more than 50 empty coal hopper cars ready to be filled. Large coal-carrying trucks now form half-mile lines.

Allan Zhang, an electrician who works at a mine here, said his employer had raised monthly pay by nearly 50 percent since the summer.

Two years ago brought “the autumn of coal, and 2015 and earlier this year were the winter of coal,” Mr. Zhang said. “Now is the springtime of coal.”

The revival of coal production shows the flaws in the country’s half-finished evolution from central planning to the free market.

China’s coal problems stem from a series of official decisions that ramped up activity from energy-intensive industries even as they curbed mining output. Speculators in China’s volatile financial markets, already prone to producing bubbles, ran up the price of coal. Weather and other setbacks haven’t helped.

Coal still produces almost three-quarters of China’s electricity, despite ambitious hydroelectric dam projectsand the world’s largest program to install solar panels and build wind turbines. Coal use in China also produces more emissions than all the oil, coal and gas consumed in the United States.

“I get a kick out of people in the West who think China is decarbonizing, because I see no sign of it whatsoever,” said Brock Silvers, a Shanghai banker who has previously served on the boards of two Chinese coal companies.

Troubled by pollution and worries about rising sea levels, China moved in recent months to rein in coal. Coal production dropped 3 percent last year — a result of that effort, but also a sign of slowing economic growth as well as a gradual shift in the Chinese economy toward American-style consumer spending and away from exports and heavy manufacturing.

That prompted the International Energy Agency to offer an optimistic reassessment this autumn: Chinese coal use peaked in 2013 and would now decline.

China’s reversal now is prompting skepticism. “There is still a peak coming,” said Xizhou Zhou, the head of Asia and Pacific gas and power analysis at IHS Energy, a global consulting group. “It’s still going to increase.”

IHS Energy forecasts that Chinese coal demand will not peak until 2026.

Johannes Trüby, a senior coal and power analyst at the International Energy Agency, said that long-term trends in the Chinese economy meant that China’s coal use would decline over all. But with China stepping up production now, he said, “We cannot exclude the possibility of a transient spike in coal demand in the next couple years that might take demand above 2013.”

Hunan great steel pipe co.,ltd will try our best to supply many mild steel pipe according to Chinese Policy.

Trump Is Off to a Slow Start on Trade Promises

WASHINGTON — President Trump keeps firing verbal broadsides at Mexico and China, but so far his new administration has not acted to keep specific campaign promises about trade policy.

Mr. Trump did not declare China a “currency manipulator” on his first day in office, as he had vowed, nor has he after his first month. Steven Mnuchin, the Treasury secretary, said on Thursday that his department was conducting a standard biannual review of the currency practices of China and other trading partners.

Mr. Trump also has not initiated the renegotiation of the North American Free Trade Agreement with Mexico and Canada, something he promised to “immediately pursue.”

“There’s definitely a huge gap between rhetoric and reality,” said Chad P. Bown, a senior fellow and specialist on trade policy at the Peterson Institute for International Economics.

Mr. Trump made trade one of his signature issues during the campaign, excoriating what he described as failed policies that have allowed foreign countries, notably China and Mexico, to profit at Americans’ expense. And he has not changed his tune since he moved into the White House.

“Take a look at Nafta, one of the worst deals ever made by any country having to do with economic development,” Mr. Trump told the cheering crowd on Friday at the Conservative Political Action Conference, held just outside Washington. “It’s economic undevelopment, as far as our country is concerned.”

Mr. Trump has fulfilled one campaign promise on trade, signing an order to withdraw the United States from the Trans-Pacific Partnership, a unsigned deal that the Obama administration negotiated with Pacific Rim nations but had not submitted to Congress for approval.

But the absence of clear action on China and Mexico is striking, both because Mr. Trump’s language remains so bellicose and because the administration has moved quickly to keep many of the other campaign promises that it made.

The “Contract with the American Voter” that Mr. Trump announced in October has proved in most respects an accurate guide to the first month of his presidency.

Mr. Trump has nominated a conservative judge to the Supreme Court and announced a freeze on federal hiring. He has reversed some Obama-era regulations and sharply shifted the government’s policies on immigration. The White House is pressing Congress to approve a new health care plan and overhaul the tax code.

Trade policy has emerged as perhaps the most notable exception.

Mr. Trump’s views on trade diverge widely from the mainstream of the Republican Party, more so than on any other issue of economic policy. And some Republicans were quick to warn Mr. Trump against protectionist measures, fearing they could damage American economic growth.

“The main point I wanted to convey is that regardless of what action the incoming president takes on trade, he and his advisers should consider the effects on agriculture,” Senator Charles E. Grassley, Republican of Iowa, declared last month after meeting with Robert E. Lighthizer, Mr. Trump’s choice to be chief trade negotiator. “I expect the new administration to work hard to maintain existing markets for Iowa and other farm states’ exports and open new markets as well.”

Another farm state Republican, Senator Ben Sasse of Nebraska, this week celebrated the 200th anniversary of the publication of David Ricardo’s economic theory of comparative advantage, which shows that trade between two nations benefits both. “It’s still brilliant & beautiful,” Mr. Sasse wrote on Twitter. He suggested in a second post that parents should read Ricardo to their children.

Mr. Trump said during the presidential campaign that he would declare China a currency manipulator on “Day 1” of his administration. He reiterated that commitment in his “Contract with the American Voter,” which said, “I will direct the secretary of the Treasury to label China a currency manipulator.”

Hunan Great Steel Pipe Co.,ltd  will focus on the economic situation and insist on supplying carbon steel pipe with high quality.