What is a welded steel pipe

Welded steel pipe, also known as welded pipe, is a steel pipe made of steel plate or steel strip after pressing and welding. The production process of welded steel pipe is simple, the production efficiency is high, and there are many varieties and specifications, but the overall strength is lower than that of seamless steel pipe.

Since the 1930s, with the rapid development of high-quality strip steel continuous rolling production and the advancement of welding and inspection technology, the quality of welds has continued to improve and the variety and specifications of pipes welded steel have increased day by day. . Welded steel pipe. Welded steel pipes are divided into straight seam welded pipe and spiral welded pipe according to the shape of the weld seam.

The blanks used for welded steel pipes are steel plates or steel strips, which are divided into furnace welded pipe, electrically welded pipe (resistance welding) and auto arc welded pipe due to their different welding processes. . Due to its different forms of welding, it is divided into two types: straight seam welded pipe and spiral welded pipe. Due to the shape of its end, it is divided into round welded pipe and special shape welded pipe (square, flat, etc.).

Debido a sus diferentes materiales y usos, los tubos soldados se dividen en las siguientes variedades:

For example:

1. Welded steel tubes for low pressure fluid transportation (GB/T3092-1993) are also called ordinary welded tubes, commonly known as clarinet tubes. It is a welded steel pipe used to transport water, gas, air, heating oil and steam and other general low-pressure fluids and other purposes. The wall thickness of the steel pipe is divided into ordinary steel pipe and thickened steel pipe; The pipe end shape is divided into non-threaded steel pipe (light pipe) and threaded steel pipe. The specification of the steel pipe is indicated by the nominal diameter (mm), which is the approximate value of the inside diameter. It is customary to express in inches, such as 11/2, etc. In addition to being used directly to transport fluids,

2. Galvanized welded steel pipe for low pressure fluid transmission (GB/T3091-1993) is also called galvanized electric welded steel pipe, commonly known as white pipe. It is a hot-dip galvanized (furnace-welded or electrically-welded) welded steel pipe used for conveying water, gas, air oil, heating steam, warm water and other general low-pressure fluids or other purposes. The wall thickness of the steel pipe is divided into common galvanized steel pipe and thickened galvanized steel pipe; The pipe end shape is divided into unthreaded galvanized steel pipe and threaded galvanized steel pipe. The specification of the steel pipe is indicated by the nominal diameter (mm), which is the approximate value of the inside diameter. It is customary to express in inches, such as 11/2, etc.

3. Ordinary carbon steel wire casing (GB3640-88) is a steel pipe used to protect cables in electrical installation projects, such as industrial and civil buildings, and the installation of machinery and equipment.

4. Straight seam electric welded steel pipe (YB242-63) is a steel pipe whose weld seam is parallel to the longitudinal direction of the steel pipe. It is usually divided into metric electric welded steel pipe, electric welded thin wall pipe, transformer quenching oil pipe, etc.

5. Spiral Seam Submerged Arc Welded Steel Pipe for Pressure Fluid Transportation (SY5036-83) is made of hot rolled steel strip as the tube blank, spirally formed at normal temperature, double-sided submerged arc welded and used for the transportation of fluids under pressure. Spiral seam steel pipe. Steel pipe has strong pressure-bearing ability and good welding performance. After several strict inspections and scientific tests, it is safe and reliable to use. The diameter of the steel pipe is large, the transmission efficiency is high, and the investment in pipeline installation can be saved. It is mainly used for pipelines that transport oil and natural gas.

6. Spiral Seam High Frequency Welded Steel Pipe for Pressure Fluid Transportation (SY5038-83) is made of hot rolled steel strip coils, spirally formed at normal temperature and welded by lap welding. high frequency, and are used for pressurized fluid transportation High frequency welded steel pipe with spiral seam. The steel pipe has strong pressure bearing capacity, good plasticity, and is convenient for welding and processing; After various strict and scientific inspections and tests, it is safe and reliable to use, the diameter of the steel pipe is large, the transmission efficiency is high, and the investment of pipeline installation can be saved. It is mainly used for the laying of pipelines for the transportation of oil and natural gas.

7. Spiral seam submerged arc welded steel pipe (SY5037-83) for general low pressure fluid transportation is made of coils of hot rolled steel strips, spirally formed at normal temperature and fabricated by welding. by automatic double-sided or simple submerged arc. -side welding. Submerged arc welded steel pipes for the general transportation of low pressure fluids such as water, gas, air and steam.

8. Spiral Seam High Frequency Welded Steel Pipe for General Low Pressure Fluid Transportation (SY5039-83) is made of hot rolled steel strip coils, spirally formed at constant temperature and welded by welding High frequency overlap for low overall pressure. Transport of fluids under pressure. High frequency welded seam steel tube.

9 Spiral welded steel pipe for piles (SY5040-83) is made of hot rolled steel strip coils, spirally formed at normal temperature and fabricated by double-sided submerged arc welding or high frequency welding. It is used for civil and architectural structures, piers and bridges. and other foundation piles.
The production process of straight seam welded pipe is simple, the production efficiency is high, the cost is low, and the development is rapid. The strength of the spiral welded pipe is generally higher than that of the straight seam welded pipe, and the welded pipe with a larger diameter can be produced with a narrower billet, and the welded pipes with different diameters can be produced with the same billet width. But compared with the same length straight seam pipe, the welding length is increased by 30-100% and the production speed is lower.
Therefore, most of the smaller diameter welded pipes adopt straight seam welding, and most of the large diameter welded pipes adopt spiral welding.