an improved chemical pressure vessel for storage , shipping and pressurized dispensing of fluid chemicals is formed with a seamless fluoropolymer inner liner permanently encapsulated within a metallic overpack . to protect the liner from the heat of welding during encapsulation of the overpack around the liner , the liner is formed with recessed indentation immediately adjacent the weld area . the indentation retains a sacrificial layer of fluoropolymer to ensure that the heat of welding will not affect the liner itself . in addition , the overpack is formed with a protective flange or &# 34 ; puddle plate &# 34 ; in the area of the weld to ensure that there is adequate isolation of the weld puddle from the fluoropolymer liner . the fact that the liner is seamless and permanently encapsulated within the overpack eliminates the need for periodic disassembly of the vessel for inspection of seams for possible leakage .