Spiral steel pipe equipment manufacturer Cangzhou Haile Steel Pipe Co., Ltd

  Spiral steel pipe spiral steel pipe is a kind of spiral seam steel pipe, which is made of strip steel coil as raw material, often formed by warm extrusion and welded by automatic double wire double-sided submerged arc welding process
The spiral steel pipe sends the strip steel to the welded pipe unit
After rolling by multiple rollers, the strip steel is gradually rolled up to form a circular tube blank with open gap
Adjust the reduction amount of the extrusion roller to control the weld gap at 1~3mm and make both ends of the weld joint flush

Standard classification
For the transportation of pressurized fluid, spiral submerged arc welded steel pipe sy5036-2000 is used, which is mainly used for the pipeline transporting oil and natural gas;
Spiral seam high-frequency welded steel pipe sy5038-2000 for pressure fluid transmission, which is welded by high-frequency lap welding, and is used for pressure fluid transmission
The steel pipe has strong pressure bearing capacity and good plasticity, which is convenient for welding and processing;
For general low-pressure fluid transmission, spiral seam submerged arc welded steel pipe sy5037-2000 is used, and submerged arc welded steel pipe for general low-pressure fluid transmission such as water, gas, air and steam is made by double-sided automatic submerged arc welding or single-sided welding

Common standards for spiral steel pipes are generally divided into: sy/t5037-2008 (ministerial standard, also known as spiral seam submerged arc welded steel pipes for general fluid transmission pipelines), gb/t9711
1-2008 (national standard, also known as technical delivery conditions for oil and natural gas industry transmission steel pipes part I: class a steel pipes (gb/t9711
2 class B steel pipes with strict requirements)), api-5l (American Petroleum Association, also known as pipeline steel pipes; which are divided into PSL1 and PSL2) Sy/t5040-2008 (spiral welded steel pipe for pile)

Sy/t5037-2008 is the standard set by the Ministry of petroleum, which is generally called the ministry standard

Gb/t9711
1-2008 national spiral pipe, steel pipe for petroleum and natural gas industry, class A
Spiral seam high-frequency welded steel pipe (sy5039-2000) for general low-pressure fluid transmission uses hot-rolled steel strip coil as pipe blank, often warm spiral forming, and adopts high-frequency lap welding method to weld spiral seam high-frequency welded steel pipe for general low-pressure fluid transmission

Spiral welded steel pipe for pile (sy5040-2000) is made of hot-rolled steel strip coil as pipe blank, often warm spiral forming, and double-sided submerged arc welding or high-frequency welding
It is used for steel pipe for foundation pile of civil building structure, wharf, bridge, etc
Production process
(1) Raw materials, i
e
strip steel coil, welding wire and flux
Before being put into operation, it must undergo strict physical and chemical tests

(2) The butt joint between the head and tail of the strip steel shall adopt single wire or double wire submerged arc welding, and the automatic submerged arc welding shall be adopted for repair welding after the rolled steel pipe

(3) Before forming, the strip steel is leveled, trimmed, planed, cleaned, transported and pre bent

(4) The electric contact pressure gauge is used to control the pressure of the pressing oil cylinder on both sides of the conveyor to ensure the smooth transportation of the strip steel

(5) Adopt external control or internal control roll forming

(6) The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, unfitness and weld gap are strictly controlled

(7) Both internal and external welding adopt American Lincoln Electric welding machine for single wire or double wire submerged arc welding, so as to obtain stable welding quality

(8) All welded welds are inspected by online continuous ultrasonic automatic flaw detector, ensuring 100% coverage of nondestructive testing for spiral welds
If there is any defect, it will automatically alarm and spray the mark, and the production workers will adjust the process parameters at any time to eliminate the defect in time

(9) The steel pipe is cut into single pieces by air plasma cutting machine

(10) After cutting a single steel pipe, each batch of steel pipes shall be subject to a strict first inspection system to check the mechanical properties, chemical composition, fusion condition of the weld, the surface quality of the steel pipe and the non-destructive flaw detection to ensure that the pipe manufacturing process is qualified before it can be officially put into production

(11) The parts with continuous acoustic flaw detection marks on the weld shall be rechecked by manual ultrasonic and X-ray
If there is any defect, it shall be repaired and then subjected to NDT again until it is confirmed that the defect has been eliminated

(12) The butt weld of strip steel and the pipe where the T-joint intersects with the spiral weld have all been inspected by X-ray television or film

(13) Each steel pipe is subject to hydrostatic test, and the pressure is sealed radially
The test pressure and time are strictly controlled by the microcomputer detection device for steel pipe water pressure
Test parameters are automatically printed and recorded

(14) The pipe end is machined so that the perpendicularity, slope angle and blunt edge of the end face can be accurately controlled