| Products Chemical Pumps Electronic Metering Pumps Mixers Fans & Blowers Dampers • Louvers • Slide Gate/Guillotine • Expansion Joints Polymaster Make Down Systems |
Dampers
Louvers Used for process gas control and/or isolation, there are four standard types of louver dampers: Parallel, Opposed, Double and Tandem Louvers. Each louver has a row of blades that are used to control or isolate the gas flow of any process system. Other advantages of the louver damper are its fast operating speed and small perimeter clearance requirement.
Parallel Blade Louvers – Used primarily for isolation applications, all blades rotate in the same direction when opening and closing. With the addition of blade seals this damper can achieve better than 99% shut off. Parallel blade louvers are also used on inlet boxes of large industrial fans to promote pre-spin to the in-rushing air, thus enhancing fan performance.
Opposed Blade Louvers – Used for flue gas control applications, the damper functions by rotating adjacent blades in opposite directions (one clockwise; the next blade counterclockwise). Operating the blades in this manner gradually decreases or increases the cross-sectional area between the blades during operation. This gradual change capability allows this louver to have good air control features as well.
Double Louvers – Designed to achieve man-safe isolation, double louvers function by pressurizing the space between the two louver dampers with “seal air”. Seal air is supplied at a pressure higher than the pressure in the flue duct, creating a safe, positive pressure environment.
Tandem Louvers – Designed to achieve man-safe isolation in clean gas streams, tandem louvers function by pressurizing the space between the two louver blade skins with “seal air”. Seal air is supplied at a pressure higher than the pressure in the flue duct, creating a safe, positive pressure environment.
Side Gate/Guillotine Slide Gate / Guillotine dampers are most commonly specified when isolation is the primary function of the damper. Guillotines are classified in two styles: Low Leak and Zero Leak. Both styles are ideal for achieving a high degree of isolation while providing low pressure drop when the dampers are in the open position. Fox Equipment provides these dampers with five types of drives: Chain & Sprocket, Rack and Pinion, Pneumatic Cylinder, Electric Jackscrews or Manual Jackscrews. The design and mechanics of the guillotine allow for ease of operation even in the most adverse duct build up conditions.
Low Leak – Primarily used for isolation purposes where low levels of leakage and pressure drop are required. Low leak applications include isolation for systems that function under negative pressure or require a tight shut-off to aid in the system’s process, ie: Shaking the bags in a large bag house.
Zero Leak – Used when man-safe isolation is required. This is accomplished by pressurizing the seal air chamber that surrounds the blade edges. When compared to a double louver, a zero leak gate requires less seal air and flange to flange space, allowing it to be used in tight runs of duct work.
Expansion JointsAdvantages & Benefits
Non-metallic expansion joints are flexible connectors in ducting and pipe systems, designed to provide stress relief by absorbing movement caused by thermal changes, vibrations and minor misalignment of adjoining ductwork or equipment.
Since the early 1960’s, the use of non-metallic expansion joints has continuously developed material technology for the design of expansion joints. Important factors must be considered when designing non-metallic expansion joints including: system design, operating temperatures, chemical resistance, pressure for belt reinforcement requirements, and thermal movements. Proper material selection and design are essential to provide long term performance of the non-metallic expansion joints.
The advantages and benefits of using non-metallic expansion joints:
- High flexibility for concurrent movements
- Minimum overall face-to-face length
- Isolates vibration
- Lower cost to ship, install, and replace
- Corrosion resistant
- Insignificant spring forces
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