Abstract: A pressure vessel having a relief area onto which a flange of a side port can be attached. The relief area includes a planar mating surface raised from the cylindrical sidewall of the vessel. A method for forming the pressure vessel includes providing a cylindrical mandrel provided with a side port spacer. Fiberglass is wrapped onto the mandrel and space. The fiberglass is impregnated with resin and the resin is cured. A metallic insert ring is embedded in a full bore open end of the pressure vessel. The ring has a cross-section having a height to width ratio of less than 0.7.

Abstract: Methods for making tubular pressure vessels from polymer-impregnated fibrous material utilize cylindrical mandrels that are helically wound while rotating about a horizontal axis. After end closure fittings are installed on the mandrel, a barrier layer having a thickness of about 0.015 in is created by helically winding a strip of nonwoven polyester fiber material which is impregnated and coated with a mixture of two resin systems, one which is promptly cured by UV radiation while the other remains uncured. The resultant barrier layer is stable and drip-free and is inspected so minor defects can be remedied. A time lag of several hours before winding the major portion of the sidewall of the barrier layer subassembly is completely acceptable if an epoxy resin plus acid anhydride curing agent system is used having an extended pot-life of 12 to 15 hours.