Frangible Roof Storage Tank

The api 650.

Frangible roof storage tank. Eemua 180 gives guidance to designers and users of such tanks on the practical steps that can be taken in design operation and maintenance to predispose the roof to shell joint to fail in preference to the shell to bottom joint thereby ensuring retention of the tank s contents. This failure is intended to vent the tank and contain any remaining fluid. 1 there is generally indicated at 1 a conventional frangible roof joint for a storage tank 3 of relatively large diameter e g fifty feet 15 2m or more. Such relatively weak roof to shell joints are known as frangible.

This video documents the research and testing on frangible joint storage tanks performed at kansas state university and thunderhead engineering. The concept of frangible roof only applies to flat bottom cone roof tanks with limited roof apex angle. The tank 3 comprises a cylindrical shell 5 having a rim at its upper edge formed by an angle 7 affixed to the outside of the shell. 01 hossein sadeghi welded tanks for oil storage.

Referring now to fig. 1 there is generally indicated at 1 a conventional frangible roof joint for a storage tank 3 of relatively large diameter e g fifty feet 15 2m or more. Referring now to fig. In such tanks the roof to shell joint is intended to fail in the event of overpressurization venting the tank and containing any remaining fluid.

However in the context of tanks the word has a specific meaning and is defined in the main tank construction standards bsen 14015 and api650. Api 650 gives rules for the design of frangible roof joints in fluid storage tanks. In the event of over pressurization the frangible roof to shell joint is designed to fail before the tank shell or the shell to bottom joint. Roof 107 5 10 roofs internal floating roof external floating roof a supported cone roof a supported dome roof a self supporting cone roof a self supporting dome roof a self supporting umbrella roof frangible roof hossein sadeghi welded tanks for oil storage rev.

Frangible is a word that means easily broken. A tank roof with a weak roof to shell connection that fails more easily than the rest of the tank under excessive internal pressure.