The invention provides a super-large-
diameter, stiffening-rib-free and thin-wall hemispherical top seal cover. The super-large-
diameter, stiffening-rib-free and thin-wall hemispherical top seal cover comprises a hemispherical top and a cylinder, wherein the hemispherical top comprises an equatorial zone, a temperate zone and an upper pole. The hemispherical top seal cover is simple in structure, low in cost, safe and reliable. The invention further provides an
assembly method of the super-large-
diameter, stiffening-rib-free and thin-wall hemispherical top seal cover. The
assembly method comprises the following steps: (1) assembling the hemispherical top on the ground; (2) mounting the cylinder; (3) mounting wind-resisting rings; (4) mounting and
welding a large-sized insert plate; (5) mounting the hemispherical top and the cylinder, wherein
assembly of the hemispherical top on the ground comprises the following steps: (a), mounting a ring foundation and a steel
structure support; (b), mounting an inside
scaffold of the hemispherical top and support ring plates; (c), mounting and
welding the equatorial zone; (d), mounting and
welding the temperate zone; (e) mounting and welding the upper pole. The assembly method has the advantages that the operation is simple, the construction cost is reduced, the construction efficiency is increased, and the construction safety and the construction quality are guaranteed.