Step 1

EDGE MILLING

Process that secures the weldability of SAW by milling both longitudinal edges of plates with groove type (X or Y shaped)

Step2

PRE – BENDING

Process that forms both edges of plate in their optimal curvature by using press and tool

Step3

PRESS– BENDING

Process that forms the entire body of plate in its optimal external diameter by using press and tool

Step4

GAP CLOSING PRESS ( POST– BENDING )

Process that minimizes the open gap (the distance between two edges) by using press

Step5

TACK WELDING

Process to secure the original form through fitting-up (GMAW) two edges of completely formed product

Step6

INTERNAL WELDING

Process to weld inside grooved edge of formed pipe by SAW method

Step7

LONGITUDINAL SEAM MILLING (GAUGING)

Process to remove tack welds by milling

Step8

EXTERNAL WELDING

Process to weld outside grooved edge of formed pipe by SAW method

Step9

ULTRASONIC TEST

Process to examine whether there are defects in welds (crack, air hole, slag, etc.)by using ultrasonic waves before cold expanding

Step10

FULL LENGTH COLD EXPANDER

Process that cold-expand pipe’s O.D from inside of pipe in order to calibrate pipe dimension and to reduce residual stress of pipe.

Step11

END FACING

Process to machine both pipe ends as per customers’ requirements

Step12

HYDROSTATIC TEST

Process to test pipe hydrostatically with constant pressure and holding time

Step13

ULTRASONIC TEST

Process to examine whether there are defects in welds (crack, air hole, slag, etc.)by using ultrasonic waves after cold expanding.

Step14

ULTRASONIC TEST

Process to examine whether there are defects in welds (crack, air hole, slag, etc.)by using the radiation (X-ray)

Step15

PIPE END RADIOGRAPHIC TEST

Process to examine whether there are defects in welds of both pipe ends by using the radiation (X-ray)

Step16

HEAT TREATMENT

Process to heat-treat entire pipe in order to get required properties (depending on type of heat treatment)

Step17

MILL COATING

Process that prevents corrosion by spreading inhibited oil on product surface