The reverse side of double-welded vertical butt joints shall be back-chipped, ground or flame-gouged before the application of the first run of welding on this side, in a manner which will leave the exposed surface accessible and satisfactory for the fusion of the weld metal to be added. At the discretion of the Principal this requirement may be relaxed when the back of the metal run is smooth and free from crevices which might entrap slag, and when the Principal is satisfied that the required weld quality will be maintained. If back-gouging is applied, grinding to bright metal is required. 显示全部