Difference Of ERW, SSAW And LSAW

chlorine factoryConveying pipe by the totally different pipe course of, may be divided into seamless steel tube (SML), mainly as oilfield gathering tube and small diameter internal high strain natural gasoline pipeline, used for …

Conveying pipe by the completely different pipe course of, may be divided into seamless steel tube (SML), mainly as oilfield gathering tube and small diameter inner high strain pure fuel pipeline, used for lengthy distance oil and gas pipeline of few in quantity, the overwhelming majority of long distance pipeline is to use excessive frequency straight seam welded pipe (ERW), spiral submerged arc welding pipe (SSAW), straight seam submerged arc welding pipe (LSAW) three. The table under for the process features of several kinds of steel pipe and high quality performance distinction:

Excessive frequency straight seam welded pipe (ERW) in response to the welding course of is divided into completely different induction welding and resistance welding two kinds, utilizing hot rolled huge strip coil as raw materials, by way of the steady forming, bending, welding, heat remedy, sizing, straightening, reducing process, comparable to weld brief in contrast with spiral welded pipe, excessive dimensional accuracy, uniform wall thickness, good surface high quality, high pressure, and so forth. However the disadvantage is that only manufacturing of small diameter thin wall pipe, weld simple era resistant, incomplete fusion, trench corrosion defects. Widely used such as city gasoline, crude oil transportation.

Spiral submerged arc welding pipe (SSAW) steel strip coil direction when the forming Angle with the middle line of the pipe forming (adjustable), forming and welding, the welding seam into spiral, benefit is that the identical specs of the steel strip can produce numerous specs of the steel tube diameter, uncooked material vary is bigger, the weld can keep away from the principal stress, the stress condition is sweet, the disadvantage is that poor geometry measurement, weld length compared with straight seam length, easy to supply cracks, porosity, slag, weld defects reminiscent of welding, welding stress is tensile stress state. The rules and regulations of general oil and fuel lengthy distance pipeline design of spiral submerged arc welding pipe can solely be used for 3, four areas. Abroad will enhance after this process shall be raw supplies as an alternative of steel plate, forming and welding, then welding and lean, chilly increasing, after welding, the welding quality is near UOE tube, at home there isn’t any such course of, is the direction of the spiral tube manufacturing facility to improve in our country. “West-east gasoline” spiral tube is still used by traditional craft production, solely the pipe hole enlargement. The United States, Japan and Germany, on the entire, damaging SSAW, do not think it’s correct to use SSAW trunk; Canada and Italy half use SSAW, Russia a small amount of use of SSAW, and have made a very strict complementary condition, as a result of historic reasons, most domestic trunk or use SSAW.

Straight seam submerged arc welding pipe (LSAW) based on single Zhang Zhonghou plate as raw material, the steel within the mold or molding machine medium-voltage (roll) into the pipe, utilizing double-sided submerged arc welding and ChengJinHang production of gap enlargement. Its completed product specification vary is vast, the toughness of the weld, plasticity, good uniformity and compactness, with massive pipe diameter, wall thickness, strong resistance to excessive strain, low temperature corrosion resistance, and many others. In the development of high strength, excessive toughness, top quality of long distance oil and gas pipeline, the steel tube are mostly straight seam submerged arc welding of giant diameter thick wall pipe. In line with the provisions of the API standard in large oil and gasoline pipelines, when the elevations, sea and metropolis populated area in class 1, 2, straight seam submerged arc welding pipe is the one specify the relevant type. In keeping with the forming strategies of different can be divided into:

UOE welded pipe, sheet steel plate after edge bending, after U form, O forming, welding, welding, mechanical chilly increasing process;

JCOE welded pipe: in keeping with “J – E – C – O” after welding, forming, welding course of by chilly hole enlargement, and many others;

HME welded pipe: the mandrel rolling technique according to the “C – C – O” after forming, welding course of by cold hole diameter, and so on