PRIME STEEL PIPE: 2017-05-21

2017/05/26

Pipe Application: Piling Steel Pipe

Piling steel pipe is the steel pipe that made of steel or strip after crimping, specifications includes φ219-φ2232 different wall thickness, the implementation of SY/T5037-2000, GB/T9711.1-1997 standards and APISpec5L standards. It is widely used in natural gas, oil, chemical, power, heat, water supply and drainage, steam heating, hydropower station pressure pipe, thermal power, water and other long-distance pipeline and piling, bridges, steel and other engineering fields. The anti-corrosion method of punching steel pipe is also started by controlling one of the process. For example, add anticorrosion coating to outer surface of the pipe, which will increase the circuit resistance and decrease the corrosion current; coupled with DC power, so that the steel pipe causes negative potential to the soil and form the cathodic protection, which can eliminate the anode and cathode.

Piling steel pipe commonly adopts spiral welded pipe and LSAW steel pipe with large diameter. The surface of steel pipe weld seam shall not have cracks, arc breaking, crater, porosity and other defects. If there are above-mentioned defects existing, repairing welding is allowed, repairing welding is allowed. It is allowed to that there are steel strip butt weld on the steel pipe, and the steel pipe is allowed to be docked by two pipe sections. The welding can be carried out by submerged arc welding or manual welding. The main production process of piling steel pipe is mainly double-sided submerged arc welding technology. More detailes about submerged arc welding process and its pros and cons, please click the hyper-link to know.

Markings of piling steel pipe

Each of the accepted piling steel pipe should be marked with fadeless paint, and we should along the perimeter of the piling steel pipe brush 50mm wide white paint at about 200mm from the inside of the pipe end. The steel pipe used for the red pipe should mark red paint to show the difference:

1. Color should be eye-catching, and should ensure that the piling steel pipe exposed to the air at least 4 months does not fade;
2. Marking color should be from the end of 200mm, and brush the entire circumference, the letter height should be at least 25mm;
3. Using metric units;
4. The number of piling steel pipe should be compiled in sequence;
5. Piling steel pipe should have number;
6. doing die marking on the end of the pipe directly facing longitudinal weld seam.

2017/05/25

Pipe Application: Pipeline Transport

Pipeline transport is a mode of transportation that using steel pipe as a transport machine to transport liquid and gas materials in long distance, is a mode of transportation that transporting oil, coal and chemical products from the place of production to market, is a special component of trunk transportation in unified transport network. The cost of using pipeline to transport oil is high than that of water transport, but it is cheaper than railway transportation. Pipeline transport features to higher transportation capacity, continuous, rapid, economical, safe, reliable, smooth and less investment, less land occupied, low cost, and it can realize the automatic control. In addition to widely used in oil and natural gas long-distance transport, but also can be used in transporting ore, coal, building materials, chemicals and food.

The main pipe used in pipeline transportation is the steel pipe, in accordance with its manufacturing process can be divided into seamless steel pipe and welded steel pipe, and welded pipe can be divided into ERW steel pipe, LSAW steel pipe, spiral welded pipe, etc. According to different enviroment and diffferent application, we will select the steel pipe produced by different technology. Prime Steel Pipe are positioned as a steel pipe manufacturer and exporter for carbon steel pipe, stainless steel pipe, seamless steel pipe, welded steel pipe, steel pipe fittings, can provide all kinds of carbon steel pipe with different specifications and standards according to the requirements of customers.

The main advantages of pipeline transportation can be summarized as follows:

(1) Large capacity
An oil pipeline can continue to complete the delivery task. According to the difference of the size of the pipe diameter, its annual transport capacity can reach to several million tons or tens of millions of tons, or even more than 100 million tons.

(2) Less land occupation
Transport pipeline was usually buried in the ground, its land occupation is very small; the construction practice of transport system proved that the part of transport pipeline buried in the underground took up more than 95% of total length of the pipeline. So the permanent land occupation is very small, respectively amounts to 3% of the road and about 10% of the railway.

(3) Short construction period and low cost
A lot of practice has proved that, compared to the same traffic volume of the railway construction period, in general,the construction cycle of pipeline transportation system is shorter than 1/3.

(4) Safe and reliable, strong continuity
As the oil and gas is flammable, explosive, volatile and easy to leak, using pipeline transport is safe, and can greatly reduce the volatile loss, and the pollution caused by the leakage of air, water and soil can be greatly reduced.

(5) Little energy consumption, low cost and good efficiency
Pipeline transportation is a continuous project, the transport system does not exist no-load travel, thus the transport efficiency of system is high. Theoretical analysis and practical experience has proved the larger the diameter of the pipeline is, the farther the shipment distance is, the larger the traffic capacity is, the lower the transportation cost is. Using oil transport as an example, the transport costs ratio of pipeline transportation, water transport, rail transport is 1: 1: 1.7.

2017/05/24

Pipeline Corrosion and Pipeline Anticorrision

As there are sulfur and acidic substances on the transported oil, and pipes are exposed to the open air and suffer wind and rain, which causes the pipe to be easily corroded.

Pipeline corrosion mainly contains several following ways, in which oxygen corrosion is the most corrosion.

1. Steel oxygen corrosion caused by the principle of the primary battery;
2. Hydrogen evolution corrosion caused by the surface of the acid sulfide (sulfur dioxide and hydrogen sulfide) caused by acid rain;
3. Carbon dioxide sour corrosion caused by atmospheric precipitation;
4. Bacterial corrosion caused by the germ that can metabolize the sulfate on the surface of the pipeline and the corrosion caused by the hydrops inner pipeline and so on.

As the causes and conditions of pipeline corrosion are not the same, the corrosion of the pipeline based on different corrosion also has the following different ways:

1. Reasonable choose a material, according to different transmission media and environmental conditions to choose different types of materials;
2. Cathodic protection, that is externally adding DC power supply, making the original anode metal turning into the cathode so that it can be protected. Or we can attach a metal that has relatively more active chemical activity to the pipeline, make the two constitute forming the original battery, so the more lively metal will be rusted and the pipeline will be protected;
3. Media processing, including the removal of corrosive ingredients in the media or the mediation of PH value;
4. Add anti-corrosion coating (such as: paint) to metal surface, to cut off the contact of steel pipe and oxygen in the air, to achieve the protective effect;
5. Add "corrosion inhibitor", the corrosion inhibitor is a special additive added in the metal equipment used to slow down the corrosion. Due to the small dosage, investment stable, obvious effect and other advantages, it is prior development direction of pipeline and other areas of anti-corrosion technology. The corrosion principle of corrosion inhibitor can be described as anti-catalytic, that counters to the principle of catalyst used in chemical production. The corrosion inhibitor will increase the activation energy required by chemical reaction, to slow down the rate of corrosion reaction.

Prime Steel Pipe will provide different kinds of pipeline anticorrision according to the different requirements of customers.

2017/05/23

Steel Pipe Application: Valves and Controls

Pipe valve is a mechanism for opening, closing, or controlling the flow of medium within pipe.

There are many types of pipe valves, and there are a variety of classification methods. If divided by purpose, valves can be divided into cut-off valve, check valve, distribution valve, etc.. If divided by pressure, valves can be divided into vacuum valve (working pressure is less than the standard atmospheric pressure), low pressure valve (PN ≤ 1.6MPa), medium pressure valve (PN = 2.5-6.4MPa) and high pressure valve (PN = 10-80MPa). If divided by the drive, valves can be divided into manual valve, power drive valve and automatic valve. There are also different classification methods, such as divided by temperature or material.

Gate valve is a gate shutter, the valve seat and the valve plate is equal, the valve plate vertical up-and-down move through the hand wheel to cut off or open the pipeline, and can adjust the opening ratio of the pipeline. Due to the characteristics of the gate, in general application, the gate valve is fully open or fully closed adjustment, less for the flow regulation. But the gate valve has advantages of good sealing performance and easy maintenance. The valve body of the shut-off valve falls vertically on the base, and the valve seat is parallel to the center line of the pipe. The fluid flow in "S" in valve body, and the fluid resistance is large. The shut-off valve is generally used for flow regulation and is easy to manufacture and maintenance, but it is easy to leak when close, and its sealing is not as good as the gate valve.

In the long-distance transmission pipeline laying, valves must be installed along the line, and the spacing should not exceed 32km, if the pipeline through the sparsely populated areas that can be properly relaxed restrictions. Along the underground oil pipelines, both ends of the pipeline when crossing and spanning in large areas of rivers, lakes, reservoirs and towns, and densely populated areas, or required according to the topographic condition, need to set the valve. The location of the shut-off valve should not be affected by geological hazards and floods, and to meet the convenience of transportation, easy maintenance, it should be set up protection facilities.

2017/05/22

Steel Pipe Application: Valves and Controls

Pipe valve is a mechanism for opening, closing, or controlling the flow of medium within pipe.

2017/05/21

Differences between Water Gas Pipeline and Galvanized Steel Pipe

The biggest difference between water gas pipeline and galvanized steel pipe is that the former is seamed steel pipe and its pressure bearing capacity is low, the later is seamless steel pipe and its pressure bearing capacity is high.

Water gas pipes are constituted by welded steel pipes with thick wall, its materials are different from galvanized steel pipes. Water gas pipe is made of low-carbon steel welded pipe. those Galvanized are called galvanized iron tubes. Those non-galvanized are called black pipes.

Galvanized steel pipe is divided into cold galvanized steel pipe and hot galvanized steel pipe. The electroplating of hot galvanized steel pipe is relatively strong, its zinc layer is thick, and there is a blue ring logo on the head of galvanized pipe. Cold galvanized steel pipe is also made by electroplating, but it is made with less technology, and its performance is far worse, no blue logo. Cold galvanized steel pipe has been banned, hot galvanized steel pipe is promoted temporary use by country.

Now the water gas pipelines used in the project are basically galvanized pipe, instrument air galvanized steel pipe and galvanized steel pipe of cable laying is using hot galvanized galvanized steel pipe to produce, since the hot galvanized pipe is more corrosion-resistant. The electrical piping on the project is thin-walled tube, it can not be under pressure.

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