Precision Flow Control, Man Safe Isolation in Hostile Environments
Flextech’s complete line of multi-blade louver dampers provides reliable modulation and isolation in many applications. All designs are heavy-duty and have multiple blades of an airfoil or monocoque profile, outboard bearings, and individual packing glands to achieve 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. The sealing efficiency of single louver dampers will vary from 91% to 99.5%. 100% isolation can be achieved with the double louver damper, which is equipped with Seal Air Purge.
Single Louver Dampers
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.
Double Louver Dampers
Single louver dampers provide ‘man safe’ isolation by incorporating two rows of blades that are equipped with flexible metal seals and a seal air system. When both rows of blades are closed, the seal air fan is energized, thereby pressurizing the space between the
blade rows to a pressure that is typically 3” W.G. above the duct operating. As a result, gas leakage across a damper assembly is prohibited.
The double louver damper can be supplied with one row of blades operating in the parallel and the other in the opposed configuration, thereby allowing modulation as well as isolation in a single unit.
Advantages –Flextech Louver Dampers
- Good modulation and control characteristics.
- Fast operating speeds.
- Little or no outside space requirements for support structure.
- All seals are internal to the duct, no leakage to the ambient side
- Lower Cost
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 Seal Air Purge. The sealing efficiency of single louver dampers
will vary from 90% to 99.5%.
Louver Damper Applications Include:
Scrubber Systems – Stack Isolation – Control Air Systems – Balancing Systems – Incinerators – Bag House
Flextech offers two basic blade types for its louver dampers:
The airfoil blade is recommended for modulation or isolation of clean to moderately dirty gas applications. The blade is constructed of two plates that 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. This configuration is used in moderate pressure and temperature environments where flow velocity does not exceed 4,000 to 5,000 feet per minute..
The monocoque blade is recommended for modulation and isolation in high-pressure and -temperature, dirty, or corrosive applications. The blade is constructed of two skins and an internal stiffener and is rigidly assembled using welded construction. For severe operating conditions, alternate blade design and construction is available.
- Relatively high strength-to-weight ratio maximizes stability and minimizes profile depth and pressure drop
- Efficient use of materials makes this design effective in applications requiring stainless steel or other alloys
- Corrosion-resistant stub shafts are welded to an internal structure at each end of the blade, forming a secure connection
- Capable of isolating extremely high temperatures without being damaged
Depending on the degree of isolation desired, the damper can be equipped with an assortment of flexible seals. A full set of seals consists of blade to blade, blade to frame, and blade to side frame. (The design of the shaft seal may vary.)
Fixed linkages are standard; however, adjustable linkages are available. The design is heavy-duty, low-cost, and ideal for both modulation and isolation.
Louver Damper Actuator Systems
Flextech’s louver dampers are supplied with a range of actuator and control systems, including Manual, Pneumatic, Hydraulic, and Electric.
Common Louver Damper Materials
Frame and Blade Materials:
Other material available