SSAW Pipe Mill Spiral Welded Seam Pipe Machine with Stable Production Line Tube Mill Line

Spiral welded pipe unit:

A spiral welded pipe unit is a steel pipe formed by rolling low-carbon carbon structural steel or low alloy structural steel strips into a pipe blank through a forming machine at a certain forming angle and then welding the spiral pipe seam with a submerged arc welding machine to form a steel pipe. Its advantage is that it can produce large-diameter steel pipes using narrower strip steel.
The spiral welded pipe unit can spiral coil the cylindrical pipe body of the strip steel, which is welded by automatic welding equipment. Based on the width of the strip steel, thick wall, and pipe diameter, the forming angle is calculated to adjust the position of each forming roller.

Usage:
Spiral welded steel pipes are mainly used for transporting oil and natural gas, and can also be used for transporting pressure pipelines such as water and steam. They are applied in petrochemicals, thermal pipelines, building structures, and other engineering projects.
The spiral welded pipe unit is divided into two methods: intermittent production with a front swing and continuous production with a rear swing. The rear swing continuous spiral welded pipe production line is mainly used for producing pipes for transporting oil and natural gas.

Process flow of spiral welded pipe unit:
Raw material stacking - uncoiling - car leveling - cutting with plate head and tail - butt welding - milling - forming - internal welding - external welding - cutting - X-ray imaging inspection - pipe end welding seam grinding - pipe end expansion - water pressure testing - ultrasonic testing - flat head - pipe end photography - weighing and measuring length - marking - oiling - packaging and warehousing

The production process for spiral welded pipe equipment:
(1) The raw materials include steel coils, welding wires, and flux. Strict physical and chemical inspections must be conducted before production investment.
(2) The butt joint of the steel strip head and tail adopts single-wire or double-wire submerged arc welding, and active submerged arc welding repair welding is used after rolling into steel pipes.
(3) Before forming, the strip steel is leveled, trimmed, planed, cleaned, transported, and subjected to edge bending treatment.
(4) Using an electric contact pressure gauge to control the pressure of the hydraulic cylinders on both sides of the conveyor to ensure smooth transportation of the strip steel.
(5) Adopting external or internal control roller forming.
(6) The use of a weld seam gap control device ensures that the weld seam gap meets the welding requirements, and the pipe diameter, misalignment, and weld seam gap are strictly controlled.
(7) Both internal and external welding is carried out using American Lincoln welding machines for single or double wire submerged arc welding, thereby achieving stable welding quality.
(8) The welded seam is inspected by an online ultrasonic active damage detector to ensure the non-destructive testing coverage of spiral welds. If there are any shortcomings, proactively alarm and spray markings, and the production workers adjust the process parameters accordingly.
(9) Use an air plasma cutting machine to cut steel pipes into individual pieces.
(10) After cutting into a single steel pipe, each batch of steel pipes must undergo a strict inspection system to check the mechanical properties, chemical composition, dissolution status of the weld seam, surface quality of the steel pipe, and undergo non-destructive testing to ensure that the pipe making process is qualified before it can be officially put into production.
(11) The areas marked with continuous ultrasonic testing on the weld seam are manually inspected by ultrasonic and X-ray inspection. If there are any defects, they are repaired and subjected to non-destructive testing again until it is confirmed that the defects have been removed.
(12) The pipes where butt welds and spiral welds intersect and T-joints are located shall be inspected by X-ray television or film.
(13) Each steel pipe undergoes a hydrostatic test, with radial sealing used for pressure. The testing pressure and time are strictly controlled by the steel pipe water pressure microcomputer monitoring device. Automatically print records of test parameters.
(14) Mechanical processing of the pipe end ensures accurate control of the perpendicularity, bevel angle, and blunt edges of the end face.

Why Choose DORCO:
Shandong DORCO Heavy Industry Machinery Co., Ltd. is located in Shandong Province and is a large-scale heavy industry machinery manufacturing enterprise in China. The company mainly engages in the design, manufacturing, and installation of large-scale equipment such as heavy industry machinery, ring rolling machines, spiral welded pipe machines, and mining machinery. Its products cover multiple series such as self-dumping, construction, environmental sanitation, logistics, and mining machinery, as well as key assembly components.

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