Why ERW steel pipe Equipments Are Being Introduced

Why ERW steel pipe Equipments Are Being Introduced

Now, a lot of metallurgical equipments in our country can be designed, manufactured and integrated by ourselves. After China jointly designing with foreign countries and summarizing the experiences and lessons of installation, commissioning, usage, maintenance, and transformation of foreign equipments, our current design has reached a high level. 

China with manufacturing capabilities can design and manufacture the world-class advanced metallurgical equipment, especially the ERW (Electrical Resistance Weld) Steel Pipe equipments under present design condition and environment. Then, why some products, especially for high-producing, high automated advanced continuous rolling pipe equipment units, are still need to be introduced? The main problem is the level of the equipment and stability, namely many accidents, poor stability and more slowly production speed.

There is a big problem that is: domestic equipments are cheap and fast. In order to seek for cheap and fast products, it is easy to reduce design level and manufacturing cost, shorten the design and debugging cycle. Therefore, the level is decreased accordingly. In addition, in order to seek for stability, our large state-owned enterprises are generally not willing to bear the liability for risk. This could be the current reason that domestic equipments can only be introduced among the private enterprises.

In addition, we should also be clear that all the highly automated and advanced equipment with high performance are not only be designed and manufactured. They all need serious debugging, commissioning and certain amount of time to a test run. This is an insurmountable stage and only in this way, domestic equipments can march towards a higher level. ERW Steel Pipe production equipments in China now are the time to enter the international market. Some developing countries, especially those who have the iron ore resources, are considering starting building ERW Steel Pipe, factory in dealing with the global crisis as this is a rare opportunity. 

The advantages of hot-dip galvanizing

The advantages of hot-dip galvanizing

1, the processing cost is low: the cost of hot-dip galvanized anti-rust coating than other low cost of paint;

2, durable: in the suburban environment, the standard hot-dip galvanized anti-rust thickness can be maintained for more than 50 years without having to repair; in urban or coastal areas, the standard hot dip galvanized layer can be maintained for 20 years without repair ;

3, the reliability is good: galvanized steel pipe and steel is metallurgical combination, as part of the steel surface, so the durability of the coating is more reliable;

4, the coating toughness: galvanized layer to form a special metallurgical structure, this structure can withstand the mechanical damage during transport and use;

5, a comprehensive protection: plating of each part can be plated with zinc, even in the depression, sharp corners and hidden place can be fully protected;

6, save time and effort: galvanizing process than other coating construction method is more efficient, and can avoid the installation site after brushing the time required.

7, the initial low cost: Under normal circumstances, the cost of hot-dip zinc coating than other protective agents is lower, the reason is very simple, other protective coatings such as sand paint is a labor-intensive processes, on the contrary hot zinc process is high Mechanization, close control of the plant construction.

8, the test is simple and convenient: hot dip zinc layer can be visual and simple non-destructive coating thickness table for testing

9, reliability: hot dip zinc specifications are generally in accordance with the BS EN ISO 1461 implementation, limits its minimum zinc layer thickness, so the rust-proof period and performance is reliable and predictable.

In Stock ERW Steel Pipe Price 2017/01/01

Updated Price List For In Stock ERW Steel Pipe On November,07,2016

Galvanized Steel Pipe Washing

Galvanized Steel Pipe Washing

1) steel pipe washing in the flow of water tank, the water should be all immersed in water, pickling straps to relax, ups and downs three to four times.
2) After washing, the pipe should be water control net as soon as possible solvent treatment to prevent the oxidation of steel.
3) cleaning water iron salt content standards may not exceed the standard, no other debris, keep clean and transparent.
4) in the washing tube, the operator is strictly prohibited across the pickling tank to prevent slipping or fall into the acid tank wounding.

Galvanized Steel Pipe Pickling

Galvanized Steel Pipe Pickling

The main reasons for the pickling of steel pipe:

(1) when the steel pipe in the feed to be strictly checked, to do not put into acid pickling unqualified steel pipe. .

(2) steel pipe in the vibration is not careful operation.

(3) pickling time and lack of hydrochloric acid content.

The main reasons for the steel pipe over pickling:

(1) hydrochloric acid content is too high.

(2) pickling time is too long.

After pickling the outer surface of steel pipe is smooth, with or without residual iron oxide, with or without grease pollution of steel pipe surface.

ERW, SSAW, LSAW (UOE) difference

ERW, SSAW, LSAW (UOE) difference
Conveying pipe by the different pipe process, can be divided into seamless steel tube (SML), mainly as oilfield gathering tube and small diameter internal high pressure natural gas pipeline, used for long distance oil and gas pipeline of few in number, the vast majority of long distance pipeline is to use high frequency straight seam welded pipe (ERW), spiral submerged arc welding pipe (SSAW), straight seam submerged arc welding pipe (LSAW) three. The table below for the process features of several kinds of steel pipe and quality performance contrast:
High frequency straight seam welded pipe (ERW steel pipe) according to the welding process is divided into different induction welding and resistance welding two forms, using hot rolled wide strip coil as raw material, through the continuous forming, bending, welding, heat treatment, sizing, straightening, cutting process, such as weld short compared with spiral welded pipe, high dimensional accuracy, uniform wall thickness, good surface quality, high pressure, etc. But the disadvantage is that only production of small diameter thin wall pipe, weld easy generation resistant, incomplete fusion, trench corrosion defects. Widely used such as city gas, crude oil transportation.
Spiral submerged arc welding pipe (SSAW) steel strip coil direction when the forming Angle with the center line of the pipe forming (adjustable), forming and welding, the welding seam into spiral, advantage is that the same specifications of the steel strip can produce various specifications of the steel tube diameter, raw material range is larger, the weld can avoid the principal stress, the stress condition is good, the disadvantage is that poor geometry size, weld length compared with straight seam length, easy to produce cracks, porosity, slag, weld defects such as welding, welding stress is tensile stress state. The rules and regulations of general oil and gas long distance pipeline design of spiral submerged arc welding pipe can only be used for 3, 4 regions. Abroad will improve after this process will be raw materials instead of steel plate, forming and welding, then welding and lean, cold expanding, after welding, the welding quality is close to UOE tube, at home there is no such process, is the direction of the spiral tube factory to improve in our country. "West-east gas" spiral tube is still used by traditional craft production, only the pipe hole enlargement. The United States, Japan and Germany, on the whole, negative SSAW, don't think it is proper to use SSAW trunk; Canada and Italy part use SSAW, Russia a small amount of use of SSAW, and have made a very strict complementary condition, due to historical reasons, most domestic trunk or use SSAW.
Straight seam submerged arc welding pipe (LSAW) based on single Zhang Zhonghou plate as raw material, the steel in the mold or molding machine medium-voltage (roll) into the pipe, using double-sided submerged arc welding and ChengJinHang production of hole enlargement. Its finished product specification range is wide, the toughness of the weld, plasticity, good uniformity and compactness, with large pipe diameter, wall thickness, strong resistance to high pressure, low temperature corrosion resistance, etc. In the construction of high strength, high toughness, high quality of long distance oil and gas pipeline, the steel tube are mostly straight seam submerged arc welding of large diameter thick wall pipe. According to the provisions of the API standard in large oil and gas pipelines, when the elevations, sea and city populated area in class 1, 2, straight seam submerged arc welding pipe is the only specify the applicable type. According to the forming methods of different can be divided into:
UOE welded pipe, sheet steel plate after edge bending, after U shape, O forming, welding, welding, mechanical cold expanding process;
JCOE welded pipe: according to "J - E - C - O" after welding, forming, welding process by cold hole enlargement, etc; HME welded pipe: the mandrel rolling method according to the "C - C - O" after forming, welding process by cold hole diameter, etc

API line pipe manufacturer

API line pipe manufacturer

API 5L line pipe according to the production process is divided into the submerged arc welding steel pipe, etc. 8. But the main use of Seamless steel tube (Seamless), high frequency straight seam Resistance Welding steel pipe (Electric - to hold the Arc Welding, shorthand for ERW), straight seam Submerged Arc Welding pipe (Longigudinally Submerged Arc Welding, shorthand for LSAW), spiral seam Submerged Arc Welding pipe, Spirally Submerged Arc Welding, shorthand for SSAW), etc.

Straight seam submerged arc welding pipe press forming method is divided into UO (UOE), RB (RBE), JCO (JCOE), etc. The steel plate in forming mould pressing U first, then pressed into an o-ring, and then evaluated for submerged arc welding, after welding are usually at the end or span range (Expanding) called the UOE welded pipe, hole diameter is not called UO of hole diameter welded pipe. The steel plate roller bend forming (Roll Bending), and then evaluated for submerged arc welding, after welding for RBE hole diameter welded pipe or not for hole enlargement RB welded pipe. Will the steel plate according to the order of type J - C - O forming, hole enlargement of JCOE welded pipe after welding or not for hole enlargement JCO welded pipe. Of the LSAW welded pipe is a widespread use of UOE. High frequency electric resistance welded pipe ERW mainly by high frequency current skin effect and proximity effect melted the tube embryo edge, then under the action of squeezing roller pressure welding, its characteristic is no foreign filler metal, heat affected zone is small, high production efficiency. Spiral welded pipe used in long distance line SSAW pipe has a long history, is our country at present mainly adopts the line pipe.

APISPEC5L pipeline standards:

API SPEC 5 l, the American petroleum institute standards

The national standard GB/T9711 - China