Floating Roof Tank Vent Design

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.

Floating roof tank vent design.

The roof rises and falls with the liquid level in the tank. The vents in the floating roof protect the roof and rim seal and accommodate liquid movement and thermal breathing. The floating roofs can be either external i e with open top tanks or internal i e inside fixed roof tanks. Floating roof tank allow the explosive gases in petroleum tanks to vent to atmosphere in a safe way.

An external floating roof tank is a storage tank commonly used to store large quantities of petroleum products such as crude oil or condensate. For normal venting api 650 g 8 3 and h 6 2 specifies vents in the fixed roof tank shell and internal floating roof. Floating roof storage tanks. For a tank with a fixed roof and internal floating roof but without a gas blanket.

Closed floating roof tank this has an internal floating roof but eliminates natural ventilation of the tank vapor space. Instead the cfrt is equipped with a pressure vacuum pv vent and may even include a gas blanketing system such as that used with fixed roof tanks these tanks are designed as in appendix c of the api standard 650. Floating roofs have been designed and used for more than a century. Today controlled gas venting in to the atmosphere is becoming more and more important due to environmental regulations.