External Floating Roof Tank Construction

The floating roofs can be either external i e with open top tanks or internal i e inside fixed roof tanks.

External floating roof tank construction.

20 liquid mounted primary seal is a primary seal that is mounted. External floating roof tanks are generally made of steel and only has a floating roof as the top covering. As there is almost no gas space between floating roof deck and oil level the evaporation loss of stored oil can be greatly reduced. 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.

The floating roof decks are usually made of welded steel plates and can be of three types double deck pontoon and pan. The roof rises and falls with the liquid level in the tank. The floating roof is made up of various elements such as fittings decks and rim sealing systems. Floating roof tanks are commonly protected against lightning ignition by bonding the floating roof to the seal shoes at no less than 3m 10ft intervals use of insulating sections in the hanging linkages covering sharp points on hangers with insulating materials and installation of electrical bond straps across each pinned hanger joint.

An external floating roof tank is a storage tank commonly used to store large quantities of petroleum products such as crude oil or condensate. 19 ladder and well is a ladder that passes through a well and is used to access the tank bottom of an internal floating roof tank. It consists of an open topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid. Tanks with external floating roofs are used primarily to contain liquids with high vapor pressures when the vapor emissions from fixed roof tanks would exceed the standards set by the local jurisdiction.