Double-end welding machine for welding flat flanges onto plastic pipes

A double-end welding machine for welding flat flanges onto plastic pipes is characterized in that a cross beam is fixed on a base, a fixed tray is fixed at the left end of the upper side of the cross beam, a sliding tray is arranged at the right end of the upper side of the cross beam, upright posts are fixed on surfaces of the fixed tray and the sliding tray, a left-reversed L-shaped bracket is fixed at the upper end of the upright post on the fixed tray, a right-reversed L-shaped bracket is fixed at the upper end of the upright post on the sliding tray, an upper cross beam is arranged above the left-reversed L-shaped bracket and the right-reversed L-shaped bracket, the right end of the upper cross beam is fixed with the left-reversed L-shaped bracket while the left end of the upper cross beam is in directional slide fit with the right-reversed L-shaped bracket, a guide chain is hung on the upper cross beam, supporting plates are fixed on the upright posts of the fixed tray and the sliding tray via plate bra