LOUVER DAMPERS	SLIDE GATE DAMPERS	DIVERTER DAMPERS	STACK ISOLATION DAMPERS
WAFER DAMPERS	RADIAL VANE DAMPERS	POPPET DAMPERS

EFFOX manufactures all basic types of Louver Dampers -- PARALLEL, OPPOSED, DOUBLE LOUVERS, and TANDEM LOUVERS.  Louvers are typically used for either isolation or control in applications requiring fast operation.

The PARALLEL design is used primarily for isolation.  The use of blade edge and jamb seals achieves minimal leakage past the closed damper.

The OPPOSED design exhibits the best flow control characteristics with moderate leakage past the closed damper.

The DOUBLE LOUVER design utilizes two banks of blades.  Zero flue gas leakage is achieved by pressurizing the area between two closed banks of blades with seal air.  The Parallel/Opposed configuration provides zero leakage yet retains good flow control characteristics.  These dampers can be found in applications where fast bypass capability is required such as in a flue gas desulphurization (FGD) system during an upset condition.  Double Louvers can also be found where overhead space is not available to install a Slide Gate damper.

The TANDEM LOUVER design utilizes one bank of blades.  Zero flue gas leakage is achieved by pressurizing the area between the two blade skins with seal air.  TANDEM LOUVERS are recommended where adequate flange to flange space is not available to install a DOUBLE LOUVER.

EFFOX DESIGN FEATURES

Bolted airfoil construction allows independent thermal expansion of the blade skins which eliminates blade warping.

Jamb seals along side frame and individual blade overlap assure tight shutoff.

Independent packing glands with outboard bearing assemblies protect the bearings from heat and flue gas contamination. Replacement of the packing can be achieved without removing the bearing.

Electric, pneumatic, hydraulic or manual actuation is available.

SAFETY FACTORS
- 300% on Drive Sizing
- 200% on Seal Air Volume at +3 inches (76mm) W.G. above duct pressure for ZERO LEAK applications.