This would be a whole lot easier if I knew how to post a link, but I don't so here goes. Go to Transport Canada's web site. Click on Safety-Transportation of Dangerous Goods-Containers-Cylinders,Spheres,and Tubes- and you will be at FAQ for cylinders that meet the requirements. There is a grandfather clause to the TC stamp requirement which excludes cylinders manufactured before January 1993 so if you have an older tank it may still be recertified providing it meets the rest of the criteria. How do I know all this? I work in the propane industry, and am also qualified to recertify cylinders. Note to TenMile: those are vertical cylinders, horizontal tanks would have feet welded to the sides to keep them in position when horizontal. Hope this helps.