Читать книгу Fabrication of Metallic Pressure Vessels - Maan H. Jawad - Страница 20

In a given class of materials, using one with a higher allowable stress is beneficial in pressure vessels with high pressures and larger diameters. For example, use of SA 516‐70 rather than SA 285C reduces wall thickness. The cost of material may remain about the same, since SA 516‐70 is more expensive per pound than SA 285C, a fact somewhat balanced by the lesser amount of material used. The reduction in wall thickness reduces cost in multiple ways, however. The time needed for rolling the vessel shell and forming the heads is less. The thickness of welds and therefore weld volume and welding time are diminished. Handling costs may be less. And depending on the fluid medium, the reduction in vessel weight might lead to smaller or thinner supports or saddles.