This Practice provides requirements for the construction of fiberglass vessels and tanks in accordance with ASME Boiler and Pressure Vessel Code Section X "Fiber-Reinforced Plastic Pressure Vessels" or ASME/ANSI RTP-1 "Reinforced Thermoset Plastic (RTP) Corrosion Resistant Equipment." This Practice describes the general requirements for the design, materials, fabrication, examination, inspection, testing, certification (ASME stamp and Supplier's Data Report), and pressure relief of aboveground fiberglass reinforced polyester, vinyl ester, and epoxy tanks and vessels having internal or external pressure from full vacuum up to the limits of Code Section X. This Practice covers shop- and field-fabricated equipment, thermoplastic-lined equipment, and dual laminate equipment. This Practice does not cover the following equipment items that are excluded from both ASME/ANSI RTP-1 and Code Section X: a. Portable or movable containers b. Hoods, ducts, and stacks c. Fans and blowers d. Vessel internals such as entrainment separators, chevron blades, packing support plates, and liquid distributor plates e. Pipe or piping f. Fully buried underground closed vessels This Practice does not cover the following equipment items that are excluded from Code Section X: a. Vessels having an inside diameter (ID), width, height, or cross-section diagonal of 6 inches (150 mm) or less, with no limitation on length or pressure. The 6-inch (150 mm) dimension excludes (150 mm) the thickness of any corrosion liner. b. Vessels containing lethal substances as designated by the owner in accordance with Code Section X Paragraph RG-113. This Practice does not cover the following equipment items that are excluded from ASME/ANSI RTP-1: a. Vessels constructed of furan, epoxy, or phenolic resins b. Vessels with non-glass structural reinforcements c. Vessels having metallic liners