Pressure vessel

A pressure vessel comprising:

• a cylindrical section;
• two bowl-shaped end wall sections wherein each of the end wall sections is disposed on an end of the cylindrical section,
• wherein a fiber retaining rib is formed on an outer surface of each of said end wall sections;
• and
• a reinforcing layer formed by winding fiber on the outer surface of said end wall section in a circumferential direction such that the fiber is retained by said fiber retaining rib.

A pressure vessel comprising:

• a cylindrical section;
• two end wall sections wherein each of the end wall sections is disposed on an end of the cylindrical section;
• and
• a connecting member connecting each of the two end wall sections together,
• wherein the two end wall sections are made of synthetic resin and wherein each of the two end wall sections include a sleeve made of one of metal and synthetic resin fixed to a central position of said end wall member, the connecting member being connected to the sleeves,
• wherein one of said sleeves is formed in a cylindrical shape having a bottom wall, the bottom wall defining a through hole therethrough, wherein an end portion of said connecting member is inserted through said through hole, and a nut is screwed onto an external thread cut into the end portion, wherein a spring member is disposed between the bottom wall and the nut, the spring member compensating for thermal expansion of the pressure vessel.