I'm making a new video on how UST's are built. To make sure I am imparting correct information, please fact-check my information below.
Fiberglass (FRP) tanks
Xerxes makes their tanks by having an employee stand on a platform and spraying fiberglass resins from the inside of the mold. (I have video clips of this process)
CSI makes their tanks just the opposite, they have a mold and an employee or machine spray the resins on the outside of the mold. (I have video clips of this process)
Steel Tanks
Steel tanks are designed and approved by the Steel Tank Institute. There are multiple regional manufacturers of steel tanks. Watco, Modern Welding, etc..
Steel tanks are made by bending one sheet of steel in a spiral. Then applying a noncorrosive coat of FRP or urethane coating over the steel of the tank. (I have video clips of this process)
What I'm not solid on:
How are the end caps double-walled?
What is the difference between steel "Clad" tanks and "Jacketed" tanks?
I know most of the regulations applicable to tanks.
STI-R922, "Specification for Permatank"
STI-P3, "STI-P3 Specification and Manual for External Corrosion Protection of Underground Steel Storage Tanks"
STI-F894, "ACT-100 Specification for External Corrosion Protection of FRP Composite Steel Underground Storage Tanks"
STI-F961, "ACT-100-U Specification for External Corrosion Protection of Composite Steel Underground Storage Tanks"
UL 58, Standard for Safety: "Steel Underground Tanks for Flammable and Combustible Liquids"
UL 1316, Standard for Safety: "Glass-Fiber-Reinforced Plastic Underground Storage Tanks for Petroleum Products"
I know all new federally regulated UST's must be double-walled.
Is there anything I am missing?