The production process of straight seam welded pipes is simple, with high production efficiency and low cost, and it has developed rapidly. The strength of spiral welded pipes is generally higher than that of straight seam welded pipes. They can be used to produce welded pipes with larger diameters using narrower slabs, and pipes with different diameters can be produced using slabs of the same width. However, compared with straight seam pipes of the same length, the weld length increases by 30~100%, and the production speed is lower.

　　Therefore, smaller diameter welded pipes mostly use straight seam welding, while larger diameter welded pipes mostly use spiral welding.

　　1. Welded steel pipes for low-pressure fluid transportation (GB/T3092-1993), also known as general welded pipes or black pipes, are used for transporting water, gas, air, oil, heating steam, and other general low-pressure fluids. Steel pipes are divided into ordinary steel pipes and thickened steel pipes according to wall thickness; according to the pipe end form, they are divided into steel pipes without threads (bright pipes) and steel pipes with threads. The specifications of steel pipes are expressed by nominal diameter (mm), which is an approximate value of the inner diameter. Inches are commonly used, and low-pressure fluid transportation welded steel pipes are also widely used as the original pipes for galvanized welded steel pipes used for low-pressure fluid transportation.

　　2. Galvanized welded steel pipes for low-pressure fluid transportation (GB/T3091-1993), also known as galvanized electric welded steel pipes or white pipes, are hot-dip galvanized welded (furnace welded or electric welded) steel pipes used for transporting water, gas, air, oil, heating steam, warm water, and other general low-pressure fluids. Steel pipes are divided into ordinary galvanized steel pipes and thickened galvanized steel pipes according to wall thickness; according to the pipe end form, they are divided into galvanized steel pipes without threads and galvanized steel pipes with threads. The specifications of steel pipes are expressed by nominal diameter (mm), which is an approximate value of the inner diameter. Inches are commonly used, such as 11/2, etc.

　　3. Ordinary carbon steel conduit (GB3640-88) is a steel pipe used in electrical installation projects in industrial and civil buildings, machine equipment installation, etc., to protect wires.

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

　　5. Spiral seam submerged arc welded steel pipe for pressure fluid transportation (SY5036-83) is a spiral seam steel pipe made of hot-rolled steel strip coils as pipe blanks, formed into a spiral shape at room temperature, welded using a double-sided submerged arc welding method, and used for transporting pressure fluids. The steel pipe has strong pressure resistance, good weldability, and has undergone various rigorous scientific inspections and tests, making it safe and reliable. The steel pipe has a large diameter, high transportation efficiency, and can save investment in pipeline laying. It is mainly used for pipelines transporting oil and natural gas.

　　6. Spiral seam high-frequency welded steel pipe for pressure fluid transportation (SY5038-83) is a spiral seam high-frequency welded steel pipe made of hot-rolled steel strip coils as pipe blanks, formed into a spiral shape at room temperature, welded using a high-frequency lap welding method, and used for transporting pressure fluids. The steel pipe has strong pressure resistance, good plasticity, and is easy to weld and process; after various rigorous scientific inspections and tests, it is safe and reliable, with a large diameter, high transportation efficiency, and can save investment in pipeline laying. It is mainly used for laying pipelines transporting oil, natural gas, etc.

　　7. General spiral seam submerged arc welded steel pipe for low-pressure fluid transportation (SY5037-83) is made of hot-rolled steel strip coils as pipe blanks, formed into a spiral shape at room temperature, and made using a double-sided automatic submerged arc welding or single-sided welding method, used for transporting water, gas, air, and steam and other general low-pressure fluids.

　　8. General spiral seam high-frequency welded steel pipe for low-pressure fluid transportation (SY5039-83) is made of hot-rolled steel strip coils as pipe blanks, formed into a spiral shape at room temperature, and welded using a high-frequency lap welding method, used for general low-pressure fluid transportation.

　　9. Pile spiral welded steel pipe (SY5040-83) is made of hot-rolled steel strip coils as pipe blanks, formed into a spiral shape at room temperature, and made using double-sided submerged arc welding or high-frequency welding, used for steel pipes for piles in civil engineering structures, wharves, bridges, etc.