Louver Dampers

Louver-DampersOur line of Louver dampers provides reliable modulation and isolation. All designs are heavy-duty and have either an airfoil or box-style (internally stiffened) blade profile, outboard bearings, and individual packing glands to achieve minimal to zero leakage around the shafts. Our designs offer quick response and fast operating cycles. The Louver damper is capable of providing accurate and repeatable flow control for all applications. 100% isolation can be achieved with the Double Louver damper which is equipped with a Seal Air System consisting of a pressure blower, a small bit of ducting, and a fabricated shutoff damper.


Single Louver dampers provide a combination of isolation and flow control. The assembly consists of a single row of blades, all of which are externally linked in a parallel or opposed configuration depending upon the desired flow pattern. The parallel arrangement is often used on fan inlets to optimize fan performance. The opposed arrangement is used where a more linear flow is desired—such as fan outlets. The sealing efficiency of Single Louver dampers vary from 90% to 99.9%.


Louver Damper1Double Louver dampers provide a combination of isolation and flow control. The assembly consists of a double row of blades, all of which are externally linked in a parallel, opposed, or a combination of the two configurations depending upon the desired flow pattern. The sealing efficiency of our Double Louver dampers is from 99.75% (without Seal Air) to 100% (with Seal Air).


Flextech offers two basic blade types for our Louver dampers. The blade skins are generally welded to the shaft and each other at the edges but can also be supplied in bolted configurations:



    Louver Damper3The Airfoil Blade is recommended for modulation or isolation of clean to moderately dirty applications. The blade is constructed of two plates which are formed around a center shaft. Our rugged design resists both bending and torsional twisting of the blade. It will also reduce vibration and fluttering while minimizing pressure loss.


    Louver Damper4The Box-style Blade is recommended for modulation and isolation for high-pressure and temperature as well as moderate to very dirty applications. A high strength-to-weight ratio maximizes stability and minimizes profile depth and pressure drop. As with the Airfoil Blade design, the blade is constructed of two skins but also uses internal stiffeners to offer a more rigid rigidly assembly.


Depending on the degree of isolation desired, the damper can be equipped with an assortment of flexible and non-flexible seals. The range from our base Step Seat to our “Full Set” of engineered seals which include Blade-to-Side Frame (Jamb), Blade Overlap, and Blade-to-Frame (Top/Bottom Sweep).
Louver Damper5



Louver Damper6Louver Damper7 

Fixed linkages are standard but adjustable linkages are available upon request. The design is heavy-duty, low-cost, and ideal for both modulation and isolation.






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.

Louver Damper8     Louver Damper9


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.