Tensile membranes structure high frequency welding machine. professional welding tents, air domes, banners, truckcovers. Tensile membranes high frequency welding machine 1. Professional for welding tent, canvas, inflatable ... pressure gap of electrodes: 250mm / 150mm / 150mm upper board: 200 x 350, 200 x 350, 400 x 600, 600 x 800, 700 ...