Spiral steel pipes can be roughly classified into four categories according to their uses: spiral steel pipes for drainage, spiral steel pipes for dredging, spiral steel pipes for piling, and spiral steel pipes for oil and gas.
Spiral steel pipes for drainage
Material of spiral steel pipes for drainage: Q235A, Q23b, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, Q345, L245, L290, X42, X46, X70, X80. The spiral steel pipe for drainage uses double-sided submerged arc welding technology. The weld is spiral. The diameter of the spiral steel pipe for drainage is generally above dn500, which is suitable for use in tap water projects, the petrochemical industry, the chemical industry, the electric power industry, agricultural irrigation, urban construction, and liquid transportation: water supply and drainage. For gas transportation: coal gas, steam, liquefied petroleum gas. The pipe body can be treated with insulation and anti-corrosion.
Dredging spiral steel pipe
Dredging steel pipe is a good steel pipe product among steel pipe products, which is widely used and applied in different industries. The production process of dredging steel pipe has extremely strict production standards. It can be processed and manufactured by certain process methods and means. The production process uses reliable raw materials for production and manufacturing. It can show important performance and role in production and use. In certain market industries, it can fully show good performance advantages and play a certain reliable performance and value.
Piling spiral steel pipe
Piling spiral steel pipe (SY5040-2000) is made of hot-rolled steel strip coil as pipe blank, spirally formed at room temperature, and made by double-sided submerged arc welding or high-frequency welding. It is used for foundation piles of civil engineering structures, docks, bridges, etc. The main reference standard is SY/T5040-2008 (spiral welded steel pipe for piles). The main specifications are a pipe diameter range: diameter 325 mm-2400 mm, a wall thickness range of 8-60mm, and a length range of 6-12m. Spiral steel pipe for piling is a spiral seam steel pipe made of steel coils, extruded at room temperature, and welded by automatic double-wire double-sided submerged arc welding.
(1) The raw materials are steel coils, welding wires, and flux. They must undergo strict physical and chemical inspections before being put into use.
(2) The head and tail of the steel strip are butt-jointed, and single-wire or double-wire submerged arc welding is adopted. After the steel pipe is rolled, automatic submerged arc welding is adopted for repair welding.
(3) Before forming, the steel strip is leveled, trimmed, planed, surface cleaned, conveyed, and pre-bent.
(4) An electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth conveying of the steel strip.
(5) Externally controlled or internally controlled roller forming is adopted.
(6) A weld gap control device is used to ensure that the weld gap meets the welding requirements. The pipe diameter, misalignment, and weld gap are strictly controlled.
(7) Both internal and external welding are performed by single-wire or double-wire submerged arc welding with an American Lincoln electric welder to obtain stable welding quality.
(8) All welds are inspected by online continuous ultrasonic automatic flaw detectors to ensure 100% non-destructive testing coverage of spiral welds. If there are defects, an automatic alarm will be sounded and a mark will be sprayed. The production workers can adjust the process parameters at any time to eliminate the defects in time.
(9) The steel pipes are cut into single pieces by an air plasma cutting machine.
(10) After cutting into single steel pipes, each batch of steel pipes must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion status, surface quality of the welds, and non-destructive testing to ensure that the pipe-making process is qualified before it can be officially put into production.
(11) The parts with continuous ultrasonic flaw detection marks on the welds are re-inspected by manual ultrasonic and X-ray. If there are defects, they are repaired and then subjected to non-destructive testing again until it is confirmed that the defects have been eliminated.
(12) The strip butt welds and the T-joints intersecting with the spiral welds are all inspected by X-ray television or film.
(13) Each steel pipe is subjected to a hydrostatic pressure test, and the pressure is radially sealed. The test pressure and time are strictly controlled by the steel pipe water pressure microcomputer detection device. The test parameters are automatically printed and recorded.
(14) The pipe end is mechanically processed to accurately control the end face verticality, groove angle, and blunt edge.
Oil and gas spiral steel pipe
Oil and gas spiral steel pipe is made of steel strips after bending and then welding. The steel pipe must undergo water pressure, bending, flattening, and other tests, and has certain requirements for surface quality. The delivery length is usually 12 meters, and it is often required to be delivered in a fixed length. Oil and gas spiral steel pipe is widely used in the oil and gas industry, chemical industry, fluid pipelines, bridge piling, infrastructure projects, and steel structures.
Post time: May-29-2024