ROUND CORNER-FOR BEST FATIGUEPERFORMANCE AND BEST VALUECorspan recommends the round corner design for allapplications. This design results in the lowest cornerstress if fit up and welding of the corner seams arecarefully controlled.

SINGLE MITER CORNER –CONVENTIONAL DESIGNCorspan also recommends the single miter design for corner construction. If a corner preference is notspecified, Corspan will use the single miter design for allconvolution profiles for lowest cost. This design allowsfor maximum amount of motion possible for a givenconvolution profile. The corner is a simple “pictureframe” construction.

DOUBLE MITER CORNER –VALUE ADDED – LOW CORNER FATIGUEThe double miter corner design offers lower corner fatigue than the conventional single miter corner orcamera corner designs. Welds are positioned away fromthe centerline of the corner and the highest stressed areaof the bellows.

CAMERA CORNER – NOT RECOMMENDEDCorspan does not recommend the use of camera cornerconstruction for rectangular metal expansion joints of anyconvolution profile. This is a method of assembly thatallows all corner seam welding to be performed on theoutside of the corner in a very accessible area with weldersof lower skill level than would be required for a singlemiter corner. However, this style corner results in deepcrevices at the corner that are corrosion initiators incertain flue gas conditions. The design also results in a reduction in movement capability.

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RECTANGULAR METAL DUCT EXPANSION JOINTS

Corspan

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