The conventional method:

Conventionally, in order to inspect a sphere tank internally and externally, scaffolding has to be erected for access.

Due to the curved surfaces, erection is both time consuming and very difficult.

For a 20 meters diameter tank, the scaffolding would normally take ten days to erect and another four days to dismantle. Besides this, adjustments to the scaffolding during the course of inspection are also a frequent occurrence as the scaffold pole may stand directly on a weld seam that needs to be inspected.

The FG SIC method:

FG developed an innovative method for the inspection of a sphere tank.

Access to the external surface is achieved by rope abseiling techniques, whereas internal access is realised by the FG Sphere Inspection Construction (FG SIC).

In no more than two days the FG SIC is erected and it is dismantled in just one day.

The use of the FG SIC allows access to all internal areas of a sphere tank for inspection activities and subsequent maintenance works and repairs in a safe, controlled and efficient way. The frame construction consists of aluminium frame sections, assembled to form a diagonal aluminium truss structure. This profile allows numerous individual platforms to be installed at any necessary location from which all inspections and/or works can be executed.

Individual sections of the assembly will be installed in the sphere via the manhole. Depending upon the overall diameter of the sphere, a configuration of the FG SIC will be assembled suitable to fit the dimensions of each individual sphere.

The FG SIC can rotate inside the sphere tank about the vertical axis, thereby allowing all surfaces to be accessed. The FG-technician easily performs the rotation procedure inside the sphere by lifting the structure up by means of a block and tackle, after which he only needs to push his hands against the shell. On reaching the desired spot, the structure is lowered again and blocked.

The FG SIC complies with the European Standards for temporary access systems and is the most efficient and cost saving way to perform activities inside a sphere tank.