Round Corner Rectangular Expansion Joint
Improves Performance in High Temperature Service at Duke Power
Rectangular metal expansion joints are preferred
by many in high temperature service. However,
the problems inherent in rectangular expansion
joints are magnified at high temperature.
Most rectangular metal expansion joints are
made with some type of hand welded miter corner
design. The miter can be a camera corner
design, a single miter design or a double miter.
All of these concepts result in a stress riser at
the corner weld seam. In a fatigue test, the corner
of a rectangular metal bellows will be the
first point of failure. At high temperatures, the
impact of a stress riser is amplified.
The round corner rectangular metal expansion
joints that Senior Flexonics Pathway produces
for Duke Power do not contain a miter weld.
Any longitudinal welds made in the corner section are
made on a flat bed welder in the tube state before the
corner is formed. By eliminating the stress riser in the
corner, the fatigue life is increased by a factor of 6 over a
miter corner design.
For information, contact Senior Flexonics Pathway.