Well, we are in a pickle. We have these radiant heating baseboard panels that heat our house. Each panel has two aluminum pipes lined with copper. Hot water heated by an oil furnace flows through the pipes. Between the two pipes on each panel is a return bend. We have a leak at one of the return bends. I would like to buy several return bends. They are metric. 12 millimeter. The return bend is made of pex tubing and metal valves. The valves say on them "Conex Sanbra" and "12mm" Does anybody know where I can buy these parts in the United States or a replacement part that would be metric?