Spiral tube

Is the low carbon 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 the pipe seam made, it can use a narrow strip steel to produce large diameter steel pipe. The specification is expressed by the outer diameter * wall thickness, and the welded pipe should ensure that the water pressure test, the tensile strength of the weld and the cold bending performance should meet the requirements.

In terms of welding process, spiral welded pipe and straight seam steel pipe welding method is the same, but the straight seam welded pipe will inevitably have a lot of T-weld, so the probability of welding defects is greatly increased, and the welding residual stress at the T-weld is large, and the weld metal is often in a three-way stress state, increasing the possibility of cracking. Moreover, according to the process regulations of submerged arc welding, each weld should have an arc starting point and an arc quenching point, but each straight seam welded pipe can not reach the condition when welding the ring joint, so there may be more welding defects at the arc quenching point.

use

Spiral pipe is mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction, is one of the 20 key products developed in China. For liquid transport: water supply, drainage, sewage treatment works, mud transport, ocean water transport. For gas transport: gas, steam, liquefied petroleum gas. For structure: for piling pipe, as a bridge; Wharf, road, building structure pipe, Marine piling pipe, etc.

Product standard

Spiral seam submerged arc welded steel pipe SY5036-83 for pressurized fluid transportation is mainly used for transporting oil and natural gas pipelines; Spiral seam high frequency welded steel pipe SY5038-83 for pressure fluid transportation, welded by high frequency lap welding method, for spiral seam high frequency welded steel pipe for pressure fluid transportation. The steel pipe has strong bearing capacity, good plasticity, easy to weld and process; General low-pressure fluid transport with spiral seam submerged arc welded steel pipe SY5037-83, the use of double-sided automatic submerged arc welding or single-side welding method for water, gas, air and steam and other general low-pressure fluid transport submerged arc welded steel pipe.

The commonly used standards of spiral steel pipes are generally divided into :SY/T5037-2000(Ministry standard, also known as spiral submerged arc welded steel pipes for ordinary fluid transportation pipelines), GB/T9711.1-1997(national standard, also known as the oil and gas industry transportation steel pipe delivery technical conditions Part I: Class A steel pipe (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 levels), SY/T5040-92(spiral seam submerged arc welded steel pipe for pile).