Quick release type pressure vessel sight glass

The utility model relates to a sight glass mounted on a pressure vessel, in particular to a quick-release type sight glass for the pressure vessel, which comprises a lower connecting edge, a gasket I, sight glass, a gasket II and an upper connecting edge, the lower connecting edge is of a cylindrical structure, a concave groove and a through hole are formed in a cylinder of the lower connecting edge, the diameter of the through hole is smaller than that of the concave groove, threads are arranged on the outer surface of the lower connecting edge, the upper connecting edge is of a cylindrical structure, a through hole, a sight glass hole and an inner threaded hole are formed in a cylinder of the upper connecting edge, and the diameter of the through hole is smaller than that of the sight glass hole. The diameter of the sight glass hole is smaller than that of the inner threaded hole, the gasket I is placed in the concave groove of the lower connecting edge, the sight glass is placed on the gasket I, the gasket