Frangible Roof Storage Tank

Api 650 is the standard governing welded tanks for oil storage.

Frangible roof storage tank.

Api 650 gives rules for the design of frangible roof joints in fluid storage tanks. Referring now to fig. Frangible roofs are normally specified as a means of providing emergency relief venting in the situation when a tank is engulfed in fire or the adjacent tank is on fire causing rapid vaporisation of the stored product such that the normal venting system cannot cope and the pressure in the tank rises to a point where the roof to shell joint fails. The api 650.

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. A vent that uses the weight of the pallet or cover to close. Such relatively weak roof to shell joints are known as frangible. 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.

The reasoning behind present api design formulas is reviewed. This failure is intended to vent the tank and contain any remaining fluid. Referring now to fig. This video documents the research and testing on frangible joint storage tanks performed at kansas state university and thunderhead engineering.

A tank roof with a weak roof to shell connection that fails more easily than the rest of the tank under excessive internal pressure. 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. This paper presents the results of an investigation into the frangible joint behavior of tanks designed to api 650 rules. It dictates tank design fabrication welding inspection and erection requirements.

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. 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.