Step 1

UNCOILING

Process to supply skelp to forming process by uncoiling the wound skelp

Step2

LEVELING

Process to flatten the uncoiled skelp

Step3

EDGE MILLING

Process that secures the weldability of ERW by milling both longitudinal edges of skelp with square-shape(I type)

Step4

FORMING

Process to transform a flat skelp into a round pipe and to prepare edge alignment for welding

Step5

WELDING

The edges of the skelp are heated by high frequency welding and are squeezed together by pressure.

Step6

HEAT TREATMENT

Process to heat-treat welds of pipe by using inductors (Normalizing)

Step7

COOLING

Process to cool the normalized welds by air and water

Step8

SIZING

Process to calibrate pipe dimension as per customers’ requirements

Step9

CUTTING-OFF

Process to cut the pipe length as per customers’ requirements

Step10

END FACING

Process to machine both pipe ends as per customers’ requirements.

Step11

HYDROSTATIC TEST

Process to test pipe hydrostatically with constant pressure and holding time.

Step12

ULTRASONIC TEST(SEAM & FULL BODY)

Process to inspect welds and base metal of pipe by using ultrasonic waves

Step13

MILL COATING

Process that prevents corrosion by spreading inhibited oil on product surface

Step14

DIMENSION / VISUAL INSPECTION / PACKING

Process that packages and decides the acceptance/refusal by confirming the size of the final product and exterior condition