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