Butterfly Dampers

Our line of Butterfly dampers are available for a wide variety of applications in round ducting where low leakage, flow control, or a combination of the two are required. Flow characteristics are similar to that of a single blade Louver Damper design and can be supplied in varying degrees of shutoff (90 to 99.9%) depending on the specific applications and seal arrangement. Design components include rolled plate steel frame with plate steel or rolled angle flanges, plate steel blade (stiffened A/R), and round bar shafts (stub and full length).

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SEAL DESIGN:

Flextech Industries offers three basic seal designs:
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  • Swing-through: Swing-through seals are used in extremely dirty applications where tight shut-off is not required. The gap around the blade can be increased or decreased to suit the customer’s individual need.
  • Step Seat: The step seat is standard for butterfly dampers and is recommended for relatively clean flue gas applications with up to a 99% sealing efficiency. This design utilizes a rolled bar which is welded to housing the blade-closed position.
  • Tadpole: A tadpole seal is also recommended for relatively clean applications. The tadpole seal is constructed of a woven high-temperature silica cover with a silica rope bulb. This design provides up to 99.9% sealing efficiency.

PACKING GLANDS:

All packing gland designs are compression-type with either a single wrap, for low to mid-temperature and clean to moderate particulate buildup, to a 3-wrap design for all other applications. The packing gland is located between the external frame and the bearing brackets for ease of maintenance.

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LINKAGE:

Butterfly Dampers5When modulation is necessary, Flextech can supply an opposed design to better control the airflow through the damper. Our typical linkage is non-adjustable but fully adjustable can be made available upon request.

ACTUATOR SYSTEMS:

Flextech can include most types of actuation requirements, i.e. electric, pneumatic, manual, etc…, as well as accommodate other requirements such as an extended shaft or mounting of a customer supplied device.