CEMLINE CORPORATION® has manufactured tanks, pressure vessels, packaged water heaters, unfired steam clean generators, and replacement tube bundles to suit customer requirements since 1935. Our products are used for ......CEMLINE CORPORATION® has manufactured tanks, pressure vessels, packaged water heaters, unfired steam clean generators, and replacement tube bundles to suit customer requirements since 1935. Our products are used for the storing and heating of water and liquids in plumbing and heating systems and industrial processes.