Spiral Steel Pipe Pile Pipe ASTM A252

Spiral Steel Pipe/SSAW Steel Pipe

l Definition

Spiral pipe, also known as spiral steel pipe or spiral welded pipe, is the low carbon structural steel or low alloy structural steel strip according to a certain helix Angle (called forming Angle) rolled into a tube blank, and then welded together the pipe seam made of it can be used to produce large diameter steel pipe with a narrower strip.

l Production procedure

1) Raw materials: strip coil, welding wire, flux. Strict physical and chemical inspection is required before putting into operation.

(2) Strip steel head and tail butt, using single wire or double wire submerged arc welding, after rolling into steel pipe using automatic submerged arc welding repair welding.

(3) Before forming, the strip steel is levelled, trimmed, planed, cleaned and transported on the surface and treated with curved edges.

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

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

(7) Both internal welding and external welding use the United States Lincoln welding machine for single wire or double wire submerged arc welding, so as to obtain stable welding specifications.

(8) The welded seam is inspected by online continuous ultrasonic automatic damage instrument to ensure 100% non-destructive testing coverage of spiral welds. 

(9) Use air plasma cutting machine to cut the steel pipe into a single.

(10) After cutting into a single steel pipe, each batch of steel pipe must undergo a strict first inspection system to check the mechanical properties of the weld, chemical composition, melting status, surface quality of the steel pipe and through non-destructive testing to ensure that the pipe making process is qualified before it can be formally put into production.

(11) The parts with continuous acoustic detection marks on the weld shall be reviewed by manual ultrasonic and X-ray, and if there are defects, after repair, they shall be nondestructive test again until it is confirmed that the defects have been eliminated.

(12) The tube where the butt weld of the strip steel and the T-joint intersecting the spiral weld are located is all inspected by X-ray television or film.

(13) Each steel pipe is tested by hydrostatic pressure, and the pressure is sealed radially.

(14) Pipe end machining, so that the end perpendicularity, slope Angle and blunt edge can be accurately controlled.Definition

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l Standard

The commonly used standards for spiral pipes are generally divided into :SY/T5037-2018 (Ministry standard, also known as spiral submerged arc welded steel pipe for ordinary fluid transportation pipes), GB/T9711.1-1997 national standard, also known as the oil and gas industry delivery technical conditions for steel pipes Part I: Class A steel pipe requirements are strict GB/T9711.2 Class B steel pipe, API-5L American Petroleum Institute, also known as pipeline steel pipe; Which is divided into PSL1 and PSL2 two grades, SY/T5040-92 pile with spiral seam submerged arc welded steel pipe.

l Sort

The spiral-seam submerged arc welding pipe for pressurized fluid transportation is mainly used for transporting oil and natural gas pipelines, and the steel pipe has strong bearing capacity and good plasticity, which is easy to weld and process. General low pressure fluid transportation with spiral seam submerged arc welded steel pipe using double-sided automatic submerged arc welding or single-side welding method for water, gas, air and steam and other general low pressure fluid transportation submerged arc welded steel pipe.

SAWH Steel Pipe

l Character

Spiral pipe features: straight seam welded pipe production process is simple, high production efficiency, low cost, rapid development. The strength of spiral welded pipe is generally higher than that of straight welded pipe, and welded pipe with larger diameter can be produced with narrower billet, and welded pipe with different diameter can also be produced with billet of the same width. However, compared with the straight seam pipe of the same length, the weld length is increased by 30 to 100%, and the production speed is lower. Therefore, the smaller diameter welded pipe is mostly straight seam welding, and the large diameter welded pipe is mostly spiral welding.