Simple unfired pressure vessels designed to contain air or nitrogen. Pressure vessels for general purposes|Bolts, Non-destructive testing, Formulae (mathematics), Pressure, Simple, Flanged fittings, Reinforcement, Gas pressure vessels, Quality assurance, Type approval, Dished ends, Acceptance (approval), Inspection, Aluminium alloys, Holes, Pressure vessels, Grades (quality), Gaskets, Brackets, Welding, Corrosion resistance, Heat treatment, Cylindrical shape, Closures, Drainage, Design calculations, Air, Welded joints, Visual inspection (testing), Nitrogen, Records (documents), Classification systems, Marking, Butt joints, Containers, Conformity, Design, Salt-spray tests, Pressure testing, Supports, Ultrasonic testing, Gas storage, Mathematical calculations, Thickness, Certification (approval), Flanges, Unfired pressure vessels, Loading, Steels, Aluminium