Pressure vessel

Abstract

Provided is a highly practical pressure vessel in which there is minimal inside diameter deformation even if openings in a center inlet/outlet part are large, and there is little pressure-induced elongation from a center to both ends. This pressure vessel is composed of a tube body made of a fiber-reinforced resin, wherein: a center inlet/outlet part that lets a liquid in or out is provided to a tube-body-axial center part on a peripheral surface of the tube body; end-part inlet/outlet parts that let a fluid in or out are provided to tube-body-axial end parts of the tube body; the tube body is configured from a helical layer of which fibers are inclined at an angle of from ±40° to less than ±50° relative to a tube-body-axial direction, a reinforcing layer of which fibers are inclined at a greater angle than the helical layer relative to the tube-body-axial direction, and a seal layer constituting an innermost layer; a breakaway part that breaks away circumferentially outward from the seal layer is provided to a position on the helical layer where the center inlet/outlet part is provided; the reinforcing layer is configured from an inward reinforcing layer and an outward reinforcing layer provided respectively to inward and outward sides of the helical layer so as to enclose the breakaway part of the helical layer therebetween; and the center inlet/outlet part is provided so as to penetrate the inward reinforcing layer, the breakaway part of the helical layer, and the outward reinforcing layer.