Pressure vessel fixing system

A pressure vessel fixation system comprising:

• a vessel having a displacement restricting part disposed on an outer circumferential surface thereof to prevent positional displacement;
• a neck mount having a seating groove where the displacement restricting part is placed;
• and
• pressurizing means coupled to the neck mount and configured to pressurize and fix the displacement restricting part,
• wherein the displacement restricting part includes a rotation restriction surface having a polygonal cross-section,
• wherein the neck mount includes a bottom block and a top block that are separated from each other and mutually coupled by a fastener,
• wherein the pressurizing means include a body with a spiral thread and a press pin disposed at a bottom of the body and configured to contact the rotation restriction surface,
• wherein the press pin is made of a metal having a lower strength than the body, and
• wherein the press pin is deformed under a compressive force generated when the body is descended and comes into contact with the rotation restriction surface.