TECHNICAL MANUAL - Sharq.biz

phase 1hauling and pre-heatingThe two surfaces to be welded are put in contact with the heating plate, takingcare to insert it correctly in order to guarantee its steadiness. Afterwards, drawnear both ends to the heating plate and apply the pressure:P 1 + P twhere P 1 is deduced from the tables supplied by the machine manufacturer andthen summed to the drag pressure P t .The pre-heating phase ends after a time t 1 sufficient as long as it forms on bothwelding ends a ring of fused material whose width is equal to:A = 0,5 + (0,1 x e n ) [millimeters]where e n is the nominal thickness of the pipe and/or fitting to be welded.26