Kind for welding pipe

Welded pipe is generally divided into straight seam welded pipe and spiral welded pipe two types.

Welded pipes by manufacturing process

Sunny Steel produce an extensive selection of welded steel pipe including ERW, HFI, EFW, LSAW, DSAW and UOE type carbon steel pipe along with their respective flanges and fittings.

Electric Resistance Welded Pipe
ERW (Electrical Resistance Welding) pipes are manufactured by cold forming of steel coil into a round cylindrical shape are used in various engineering purposes..
High Frequency Induction (HFI) Welded Pipe
In High Frequency Induction (HFI) Welded Pipe production process, hot rolled steel coils are fed with a high capacity accumulator in order to achieve continuous welding.
Spiral submerged-arc welding pipes
Spiral submerged arc welding is its forward direction and forming tube centerline hose reel molding angle side molding edge welding and weld them into a spiral.
Electric Fusion Welded Pipes
EFW Pipes
The EFW pipe divison consists of a JCO forming press, helical / spiral mill, inside and outside welding system, heat treatment furnace and testing facilities.
Longitudinally Submerged Arc Welded Steel pipes
LSAW (Longitudinally Submerged Arc Welded Steel pipes) in leaflets plate as raw material, the steel plate in the mold or molding machine pressure (volume)...
Double Submerged Arc Welded (DSAW) steel pipe
Double Submerged Arc Welded (DSAW) steel pipe is available in straight and spiral welded formats and used in a variety of applications.
UOE (Uing and Oing forming) Pipes
UOE(Uing and Oing forming) is a method used for production of longitudinally welded large diameter pipes.
J-ing, C-ing and O-ing pipes
J-ing, C-ing and O-ing process with characteristics of high forming accuracy and efficiency as well as balanced...
SAWPIPE commonly refer to large diameter weld pipe, it can be classified into LSAW and SSAW .
Welding process

From the welding process, Welding method of the spiral welded pipe and straight seam steel pipe is consistent, but the straight seam welded pipe will inevitably have a lot of t-shaped weld, so the probability of weld defects is also greatly improved, and the t-shaped seam welding residual stress is larger, the stress state of the weld metal are often in a three-way increases the possibility of a crack.And, according to the regulations of submerged arc welding process, each weld shall have arc and arc in, but every straight seam welded pipe when weld girth, can not meet the conditions, thus there may be more at arc welding defects.

Strength characteristics

When the pressure in the pipe withstand, usually two main stress on the wall, that the radial and axial stress stress δ. Synthetic weld stress δ, where α is the helix angle of the spiral weld pipe. Spiral welded seam degree helix angle is generally so synthetic, and spiral weld Longitudinal stress is the main stress. Under the same operating pressure, spiral pipe of the same diameter than the Longitudinal wall thickness can be reduced.

Hydrostatic burst strength

By the relevant comparison test to verify the spiral welded pipe and Longitudinal yield pressure and burst pressure measured and theoretical values ​​match, the deviation closer. But whether it is the yield stress or burst pressure, were lower than the Longitudinal spiral welded. Burst test also shows that the rate of deformation ring spiral welded pipe bursting Longitudinal significantly greater than the mouth. Thus confirmed that the spiral welded plastic deformation capability than Longitudinal, blasting mouth generally confined to a pitch, which is the extension of the spiral weld to rip from a strong binding effect due.

Toughness and fatigue strength

The trend of the development of the pipeline is of large diameter and high strength. With the increase of the diameter of the pipe and the steel grade increases, the greater the ductile fracture tip steady expansion trend. Although spiral welded pipe and straight seam welded pipe has the same level, spiral welded pipe is with high impact toughness. Transmission pipelines due to the amount of change in the actual operation, the pipe is subjected to random alternating load effect.

Weled steel pipe specification, Standard and identification

Welded steel pipe (steel pipe manufactured with a weld) is a tubular product made out of flat plates, known as skelp, that are formed, bent and prepared for welding.

Hot dip galvanizing

Galvanized pipe process characteristics

What is Galvanized Steel Pipe? Galvanized steel can be made into a strong plumbing or tubing material -- one that resists corrosion from exposure to water or the elements. It has been used used for water-supply pipes or as a strong tubing for outdoor applications.


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