- Accessories and
are available with weld ends or custom welded flanges
for bolt-up connections. Metal bellows can be supplied in one to three plys in a variety of materials.
Flanges can be provided to match customer bolt patterns.
Fixed and floating flanges available.
Weld ends or pipe ends provide a
way for welding directly to the ductwork.
Beveled or square cut ends are provided.
||The flow liner
protects the corrugated metal bellows from abrasion and
reduced buildup of particulate. The liner also helps to provide
a laminar flow. Materials include: carbon steel, corten,
stainless steel and AR plate.
The metal bellow cover provided to protect from external
environment and dirt build up. Provided in stainless steel
or galvanized steel.
Control Rods/Limit Rods
Control rods provide stability and/or limit
movements. This helps over-extension or compression of the
joint which could cause damage.
The bellows convolution is the element of
the bellows that makes its flexibility possible. Each convolution can be
likened to a pair of thin washers which can deflect easily by bending
parallel to the bellows centerline. The amount of flexibility of each of
these washers is a direct function of the height of the convolution, and
the height is limited by both the pressure and the ability to form the
convolution. Except in a very few applications, a single convolution is
not capable of providing a sufficient amount of movement.
The convolution can only deflect in an
axial direction in any radial plane. Therefore, a single convolution can
only accept movement in an axial direction, or angularly about its
center. A single convolution is incapable of accepting lateral
deflection. Therefore, the metal bellows usually will have several
convolutions. At certain calculable critical pressures each convolution
will experience a deformation of the side walls known as in-plane
instability. Every bellows also has a calculable critical pressure at
which a phenomena known as "squirm" or column instability will occur.
Squirm is similar to column buckling and is an effect exhibited by the
convolutions as a whole, rather than individually as with in-plain
Each bellows has been computer designed
and analyzed to assure that each of the above pressure and movement
considerations and limitations have been taken into account.