Floating Roof Tank Grounding

Floating roof tanks are especially vulnerable to the direct and indirect effects of lightning.

Floating roof tank grounding.

An external floating roof tank is a storage tank commonly used to store large quantities of petroleum products such as crude oil or condensate. Retractable grounding assembly 750 rga 750 product overview comprehensive lightning strike protection for floating roof tanks. The atex approved patented retractable grounding assembly rga substantially reduces the risk of tank fires by subduing sustained arcs during lightning events and other electrical phenomena. The rga is able to do this better than other methods because designers analysed and found ways to overcome the weaknesses of other traditional devices for grounding floating roof tanks.

It consists of an open topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid. As there is almost no gas space between floating roof deck and oil level the evaporation loss of stored oil can be greatly reduced. When these lightning currents arc across the roof shell interface they can ignite any flammable vapours present with devastating effect. Uses patented innovative active monitoring technology to detect any change in electrical bond resistance between a floating roof and the storage tank s grounding system.

As opposed to a fixed roof tank there is no vapor space in the floating roof tank. The roof rises and falls with the liquid level in the tank. The external floating roof tank has a floating roof deck which is covered on the surface of oil and floats up and down with the oil level. Floating roof tanks seals on floating roof fr shall be bonded to the shell by shunts type 302 28 gauge 2 inch wide stainless steel straps at maximum 10 ft spacing all metal tanks all must be grounded by one of the following.

New aluminum cable originally developed for marine use greatly improves corrosion resistance and is highly resistant to hydrogen sulfide h2s. Internal floating roofis where the roof floats on the product in a fixed roof tank. Floating roof tank fires are common there are 15 to 20 tank fires per year and over half of them involve floating roof tanks frt. Comprehensive lightning strike protection for floating roof tanks.

Direct or a nearby lightning strike can cause electrical current to flow across the tank shell and roof. 1 tank connected without insulating joints to a grounded metallic piping system. Floating roof tanks is which the roof floats directly on top of the product. The rga 750 is pretensioned at the factory so no on site tensioning is required.

There are 2 types of floating roof. The groundguardian active floating roof tank monitoring system developed by alltec alerts you to resistive changes in your roof to shell bond maintaining a safe work environment and reducing risk. External floating roofis where the roof floats on the product in an open tank and the roof is open to atmosphere. The rga is able to do this better than other methods because designers analyzed and found ways to overcome the weaknesses of other traditional devices for grounding floating roof tanks.