Seamless Pipe Meaning

Seamless steel pipe is widely used in engineering and construction. It is a hollow steel strip without joints. It is mainly used for pipelines for conveying liquids. Its appearance is different from that of general steel. It is one of those heavy steels. It has strong corrosion resistance and general corrosion resistance. It will not rust. This property prolongs the service life of seamless steel pipes. The most important thing is that it is very clean and has no toxins. Seamless steel pipes have strong mechanical resistance compared with other plastics. No matter how high the temperature is, the use of seamless steel pipes is not affected by impact. Its installation method is the same as other pipes. It can replace other pipes to convey water and other liquids.

Seamless steel pipe is made of a whole round steel perforated. There is no weld on the surface of the steel pipe, so it is called seamless steel pipe.

1. According to the production method, seamless steel pipes can be divided into hot-rolled seamless steel pipes, cold-rolled seamless steel pipes, cold-drawn seamless steel pipes, and extruded seamless steel pipes.

There are two main production processes of seamless steel pipe (cold rolling and hot rolling):

①The main production process of hot-rolled seamless steel pipe (△main inspection process):

Pipe blank preparation and inspection△→Pipe blank heating→Pipe perforation→Pipe rolling→Pipe blank reheating→Sizing (reducing) diameter→Heat treatment△→Finished pipe straightening→Finishing→Inspection△(Non-destructive, physical and chemical, bench inspection)→Warehousing

②Main production process of cold-rolled seamless steel pipe:

Pipe blank preparation→Acid pickling and lubrication→Cold rolling (drawing)→Heat treatment→Straightening→Finishing→Inspection→Warehousing

It can destroy the casting structure of the steel ingot, refine the grains of the steel, eliminate the defects of the structure, make the steel structure dense, and improve the mechanical properties. This improvement is reflected in the rolling direction, so that the steel is no longer isotropic to a certain extent; the bubbles, cracks and looseness formed during casting can also be welded together under high temperature and pressure.

Seamless pipe is a precision seamless steel pipe that is cold-drawn or cold-rolled for machinery and hydraulic equipment, with high dimensional accuracy and good surface finish. The cold rolling process refers to the method of processing steel plates or steel strips into various types of steel by cold processing processes such as cold bending and cold drawing. Cold-rolled seamless pipes include not only general steel pipes, medium and low pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, and petroleum cracking steel pipes, but also thin-walled carbon steel pipes, thin-walled alloy steel pipes, thin-walled stainless steel pipes, and special-shaped steel pipes. The outer diameter of hot-rolled seamless pipes is generally greater than 32mm, and the wall thickness is between 2.5mm-75mm; the outer diameter of cold-rolled seamless pipes is generally less than 6mm, and the wall thickness is less than 0.25mm; the outer diameter of thin-walled pipes is generally less than 5mm, and the wall thickness is less than 0.25mm. The dimensional accuracy of cold-rolled pipes is generally higher than that of hot-rolled pipes.

1. Fast forming speed, high productivity, no damage to the coating, and profiles can be made into various shapes to adapt to different use conditions. The cold rolling process can cause large plastic deformation of steel, thereby increasing the yield point of steel. 2. The cold rolling process can destroy the casting structure of the steel ingot, refine the grains of the steel, eliminate organizational defects, make the steel structure dense, and improve the mechanical properties of the steel. This improvement is mainly reflected in the rolling direction, and to a certain extent, the steel is no longer an isotropic body. The bubbles, cracks, shrinkage holes, etc. formed during casting can be repaired under high temperature and high pressure.

Seamless pipes are available in the following specifications: ASTM A53, A106, A252, A333, A335, A501, A523, A589, API 5L and API 5CT. The most common seamless pipe is A106B. End treatments of seamless pipes include beveled or square cut flat ends. Seamless carbon steel pipes are available in black, bare, galvanized or epoxy coatings. Steel pipes are usually available in lengths of 21 feet. It is also available in single random lengths (SRL) ranging from 17 feet to 24 feet. Double random lengths (DRL) refer to pipes with a length of at least 37 feet to 44 feet.

The weight per meter of seamless steel pipe is W=0.02466*S(DS).

Symbol meaning: D=outer diameter, S=wall thickness.

For example, for a seamless steel pipe with an outer diameter of 60mm and a wall thickness of 4mm, calculate the weight per meter.

Solution: Weight per square meter = 0.02466*4*(60-4)=5.52Kg.

The theoretical weight calculation formula for seamless steel pipes is W=0.0246615(DS)*SW.

Seamless steel pipes have a hollow cross-section and are widely used as pipelines for conveying fluids, such as pipelines for conveying oil, natural gas, coal gas, water and certain solid materials. For most seamless steel pipe manufacturers in China, the maximum outer diameter of the original seamless pipe they produce is 20 inches, 508 mm. Due to equipment limitations, it is usually less than 16 inches, 406.4 mm. If customers want to purchase seamless steel pipes larger than the above size, they need to undergo hot expansion. But usually the quality of such hot-expanded seamless steel pipes cannot be compared with the original seamless steel pipes. In contrast, welded steel pipes do not have these limitations and range in size from 1-1/2 inches (48.3 mm) to 100 inches (2540 mm).

Baowi-steel is a manufacturer of seamless steel pipes in China. We are committed to providing high-quality products and services. If you need them, you can leave a message for inquiry.