Model Boiler parts to make 4'' inch or 100mm Horizontal Steam Boiler. Diameter 4'' or 100mm x 200 long copper tube. Flue tube 1'' or 25mm inside diameter copper tube. Firing tube 2'' or 51mm copper tube. Cross tubes 3/8'' copper tube supplied. Ceramic gas burner 50mm to fit firing tube. 2 x 100mm Copper end caps 1 x Water gauge with blow off valve 1 x Pressure gauge 100 PSI 1 x Safety relief valve. 1 x Steam valve. 1 x Check valve. 1 x Inline displacement lubricator. You will need some basic engineering skills to build this model boiler and probably the use of a lathe . Finished boiler picture is sample only .