How to Increase the Stability of the SSAW Steel Pipe?

After the production of SSAW steel pipe, it should be stored.If we don’t do some measures to keep its stability, it will rust and be corroded. So we will talk about how to increase the stability of the spiral welded pipe today. Generally speaking, we have followed methods:

1. Small and medium-sized steel, wire rod, rebar, steel pipe with medium diameter, wire and wire rope, etc., can be stored in well-ventilated shed, but must put covering in the upper part of the goods and underlay at the bottom of the goods.

2. Some small steel shape, sheet steel, steel strip, silicon steel sheet, small diameter or thin-walled steel pipe, all kinds of cold-rolled or cold-drawn steel and the metal products with high prices and easy-to-corrode can be stored in warehouse.

3. The ground or warehouse to store spiral steel pipe should choose the place where is orderly and clean, and it is easy to fluently drain away water. It should stay away from the factories and mines that products harmful gases or dust. We also need to remove the weeds and all debris to keep the steel clean on the ground.

4. Large-scale structural steel, steel rail, large diameter steel pipe, forgings, etc. can be opened stack.

5. In the warehouse, SSAW steel pipe should not be stacked with the acid, alkali, salt, cement and other materials that have corrodibility on steel together. Different varieties of steel should be stacked separately, to prevent confusion and prevent contact corrosion.

Submerged Arc Welding Process of SSAW Steel Pipe

SSAW steel pipe refers to the metal pipe with spiral seam that using submerged arc welding process to weld. There are complete production line of SSAW steel pipe in Prime Steel Pipe, we are positioned as a steel pipe manufacturer and exporter for spiral welded pipe. If there is a need, please contact us without hesitation, we will do our best to meet your requirement.

Submerged arc welding (including submerged arc welding and electroslag welding, etc.), its full name is submerged automatic arc welding, it is a kind of method that arc burns under the flux layer to weld. Its inherent advantages (including stable welding quality, high welding productivity, no arc and few dust, etc.) makes it become the main welding methods used in pressure vessel, pipe section manufacturing, box beam and other important steel structure production.

Advantages of SSAW steel pipe:

1. High production efficiency. On the one hand, the wire length is shortened, the current and current density are improved, therefore, the penetration depth of the arc and the deposition efficiency of the welding wire are greatly improved. Generally, single-sided melting depth of can be up to 20mm if do not open the groove. On the other hand, due to thermal insulation of flux and slag, the arc basically has no loss of heat radiation, welding spatter is also few. Although the heat loss for melting the flux is increased, the overall thermal efficiency is still greatly increased.
2. High quality of weld seam. The protective effect of the slag from the air is good, the welding parameters can be stabilized by automatic adjustment, the requirement of the welder's technical level of is not high, the composition of weld seam is stable and the mechanical performance is better.
3. Good working conditions. In addition to reducing the labor intensity of manual welding operations, it does not have arc radiation, which is the unique advantage of submerged arc welding.

Disadvantages of SSAW steel pipe:

The flexibility of submerged arc welding is not as good as manual welding, it is generally only suitable for the weld seam that in horizontal position or small gradient. Workpiece edge preparation and assembly quality requirements are higher, which is cost more working time. Due to using submerged arc welding, we can not see the bath and weld formation process, so the welding specification must be strictly controlled.

Advantages and Disadvantages of Welded Steel Pipe

The technology of welded steel pipe is continuous online production. So the thicker the wall thickness is, the greater the investment in the unit and welding equipment is, and welded steel pipe will have less economical efficiency and practical applicability. The wall thickness is thinner, its input-output ratio will be decreased accordingly. The process of the product determines its advantages and disadvantages. In general, the welded steel pipe with high precision, uniform wall thickness, high brightness of tube inside and outside (surface grade of steel plate determines the surface brightness of steel pipe), can be fixed length wilfully. Therefore, welded steel pipe reflects its economy and aesthetics in the high-precision, low-pressure fluid applications.

The production process of welded steel pipe is simple, the production efficiency is high, the cost is low, and develops rapidly. The strength of the spiral welded pipe is generally higher than that of the straight seam welded pipe. The pipe with larger diameter can be produced with the narrow billet and the pipe with different diameter can also be produced with the same width billets. However, compared with the same length of the straight pipe, the length of weld seam increased by 30% to 100%, and the production rate is low. Therefore, the pipes with smaller diameter are mostly used straight welding, the welded steel pipes with large diameter are mostly used spiral welding.

Prime Steel Pipe is positioned as a steel pipe manufacturer and exporter for all kinds of welded steel pipes in different standard and dimension, including ERW steel pipe, LSAW steel pipe, SSAW steel pipe, etc..

Material and Standard Classification of SSAW Steel Pipe

Material of SSAW steel pipe:

SSAW steel pipe (also called spiral welded pipe) is the steel pipe with spiral seam that using strip coil as raw material, extrusion forming under normal temperature, and welding by automatic Double wire double-sided submerged arc welding process. The material of it includes: Q235A, Q23b, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, Q345, L245(B), L290(X42), L320(X46), L485(X70), L555(X80).

Standard classification of SSAW steel pipe:

1. Spiral welded pipe (SY5036-83) used for pressurized fluid transportation is mainly used for conveying oil and natural gas pipeline.
2. Spiral seam high-frequency welded steel pipe (SY5038-83) used for pressurized fluid transportation, it is welded with high-frequency welding method. The loading capacity of it is powerful, the plastic is good, and it is easy to weld and machine shaping.
3. Spiral welded pipe (SY5037-83) used for general low-pressure fluid transmission, it is welded with double-sided automatic submerged arc welding method or one-side welding method, it is mainly used for water, gas, air and steam and other general low-pressure fluid delivery.

Now general standards for SSAW steel pipe is generally divided into: SY/T5037-2000 (ministerial standard, also known as spiral submerged arc welded steel pipe for ordinary fluid transportation pipeline), GB/T9711.1-1997 (Chinese standard, also known as pipe for oil and gas industry transportation, API-5L (American Petroleum Institute, also known as pipeline steel pipe; which is divided into PSL1 and PSL2), SY/T5040-92 (spiral seam submerged arc welded pipe for pile).

Prime Steel Pipe as a excellent manufacturer and exporter of steel pipe, will provide the spiral welded pipe with highest quality and the most comprehensive service for our customer. If you are interested in our products, you can click the hyper-link to view details.

The Welding Quality of Welded Steel Pipe

Welding quality of welded steel pipe refers to the degree to which the welding product meets the design technical requirements. Welding quality not only affects the use performance and life of welding products, more importantly, affects personal and property safety. Welding quality is usually ensured by design quality, processing quality, quality inspection and post-weld treatment and other links of the product.

Design Quality

The type of joint used in the welding product and its calculated strength should meet the actual carrying capacity. Welding method should be suitable for the characteristics of components, and its economical efficiency should be good. The welding process should be able to minimize stress, deformation and stress concentration. Production labor and material consumption should be as small as possible, the convenience of flaw detection should also be taken into consideration when design the joint.

Processing Quality

The performance of adopted the base metal, wire, flux or welding electrodes and other welding materials should meet the design requirements. The performance of welder, auxiliary equipment and testing equipment should be good. Before welding, the welding material should be dried according to the provisions, the welding groove of workpiece should meet the requirements and remove the cutting residue, cracks and dirt.

Quality Inspection

Quality inspection runs through the whole production process from design to finished product, we must ensure that the test method used in the quality inspection process is rationality, the reliability of the testing instrument and inspection staff technical level. The properties of the joints, physical properties, mechanical properties, microstructure, chemical composition, corrosion resistance, appearance dimensions and welding defects of products after welding should be checked by means of various inspection methods.

Welding defects can be divided into external defects and internal defects. External defects include: excess height does not meet the requirements, welding tumor, undercut, crater, arc burns, surface pores, surface cracks, welding deformation and warping. Internal defects include: cracks, not penetration, not fused, slag and porosity. The most harmful in welding defects is the crack, the followed is lack of penetration, incomplete fusion and slag inclusion, pores and structure defect. Individual flaws are allowed to exist. The number and the nature of allowed defects are determined by the using conditions and the quality assessment criteria of the product. If the surplus height of welding line is too high, it is allowed for those products by the static load, but it is not allowed for those products by cyclic fatigue loading in high frequency, even the normal excess weld metal also has to be cut off. The presence of welding defects is related to the groove processing and assembly accuracy, the rigor degree of the welding process, the technology of the welder and other factors.

What is Welded Steel Pipe?

Welded steel pipe, also known as welded pipe, is the steel pipe that made of steel plate or steel strip after crimped and welded. The production process of welded steel pipe is simple, production efficiency is high, variety specifications are many, the investment of equipment is little, but its general strength is lower than the seamless steel pipe. Since the 1930s, with the rapid development of high-quality strip continuous rolling line and the improvement of welding and inspection technology, the quality of welding line has been increasing continuously, and the specifications of welded steel pipes have been increasing. And welded pipe have replaced the seamless steel pipe in more and more field. Sewing steel pipe. The welded steel pipe is divided into straight seam welded pipe(also called LSAW steel pipe) and spiral welded pipe(also called SSAW steel pipe) according to the form of welding line.

Production process of LSAW steel pipe is simple, production efficiency is high, cost is low, and it develops rapidly. The strength of the SSAW steel pipe is generally higher than that of the LSAW steel pipe, and the SSAW steel pipe with larger diameter can be produced with the narrow billet. And it also can use the billet with the same width to produce t SSAW steel pipe with different diameter. However, compared with the straight seam welded pipe in identical length, the length of welding line increased by 30 to 100%, and the production rate was low.

Therefore, pipe manufacturers usually use straight seam welding to produce the smaller diameter of the pipe, use spiral welding to produce large diameter welded pipe.

Connection Modes of Oil Pipelines

Several days ago, we introduced the types of tube that used in oil pipeline, today, we will share the connection modes of oil pipelines for people those interested in this aspect.

Oil pipeline must use a certain connection to form a complete system. Connection methods of pipeline are mainly three categories, including screw thread, welding and flange connection.

When the pressure is not high, the pipe with small diameter can be connected by using screw thread this method. This connection method is very convenient, but most of the diameter of oil pipelines are generally larger, so other two connection methods are used commonly.

The pipeline that DN≥50 basically uses welding method to connect. Welding has many advantages, such as convenient construction, strong, tight and saving steels. The general straight pipe or bends those parts do not need to tear down can use this method.

The connection of pipes and valves or other equipment (such as: pump) and the parts those need to disassemble of pipeline need to use flange to connect. In order to ensure the tightness of the flange connection, we also need to use a relatively soft flange grommet to assist on both sides of the flange. According to the production process, flange can be divided into flat welding, thread, butt welding, loose tube and blind plate and other types. Except blind plate flange, others are all used in interconnection between the pipeline. If you need to connect different diameters of the pipeline, you can use the adapter flange that two diameter corresponding. The blind plate flange is used to close the end of the pipe head. Therefore design of it make it can withstand greater bending stresses.