This section of the PVRC lnterpretive Report of Pressure Vessel Research covers the effects of fabrication and environmental conditions on pressure vessel behavior.The first item considered is forming operations.Forming of single-curvature shapes is conducted in rolls or presses, whereas forming of double-curvature shapes is conducted in presses or spinning equipment. For both shapes, forming temperature depends on material, thickness, radius, heat treatment, strength, ductility, and equipment limitations.