Flange And Flued Bellows Expansion Joints

Flange and flued bellows can be the right answer to piping, ducting and vessel thermal growth problems over that of conventional thin walled metal bellows.Cracking of any type is very difficult to weld repair on thin bellows but can be performed with plant maintenance staff on heavy walled bellows. The thicker wall also hold up better to corrosion attacks - an added benefit is the common use of carbon steel material which is almost never used on thinner bellows in lieu of stainless steel or nickle alloys. drain couplings can also be added to the bottom of the flanged and flued convolution to prevent a build up of condensate.Some Information on Steel Fabrications The most common application for flanged and flued expansion joint is ASME code heat exchangers, and is the preferred bellows of choice as the movement is exclusively axial. The heavy walled, deep convolution is durable, and should last the life of the exchanger. The down side to the heavy wall design is the increase in stiffness which can over-stress the heat exchanger tube sheet. Many engineering firms have banned the use of thin walled bellows expansion joints in process piping due to fear of field misapplications that may result in a failure. With a flanged and flued bellows those fears are unfounded as the heavy wall is about as fool proof an expansion joint as can be expected. There are many different flange standards to be found worldwide.The ANSI number does not directly relate to a pressure rating, but to a class of flange. "Pressure Classes" of piping are usually developed for a process plant or power generating station; these "pressure classes" may be unique to the specific corporation, Engineering Procurement and Construction (EPC) contractor, or the process plant owner.