Double Louvre Damper Gate
Twin-row louvre gate with sealing air between the blade banks — 99.9 % sealing efficiency and pressure loss below 50 Pa when open.
Flue duct dampers, air dampers and duct valves
Fourteen product families covering every isolation and regulating position between the boiler outlet and the stack. Standard ranges in stock sizes, everything else built to your drawing.
Flue Duct Damper Gate
Heavy-duty isolation gates for boiler flue ducts, with single or double blade rows.
Flue Gas Damper Gate
Double louvre gas dampers with sealing air, designed for zero-leakage duty.
Flue Duct Air Damper
Regulating and shut-off dampers for cold and hot air ducts with linear characteristics.
Desulfurization Damper Gate
Corrosion-resistant gates for wet FGD inlet, outlet and bypass service.
Round Air Damper
Circular isolation and throttling dampers for round air and flue ducts.
Square Air Damper
Rectangular multi-blade dampers for large air ducts and rectangular flue runs.
Isolation Gate
Guillotine-type gates that give a physical, visible break in the gas path.
Flap Gate
Light-duty flap dampers for low-pressure air and dust-laden gas lines.
Coal Gate
Abrasion-resistant gates for coal bunkers, feeders and pulverizer outlets.
Damper Valve
Compact blade valves for tight shut-off on small and medium ducts.
Slide Gate Valve
Saddle-seat slide gates with hard and soft sealing for dust-laden ducts.
Isolation Valve
Zero-leakage valves for isolating gas and air branches during maintenance.
Gate Valve (Duct Type)
Rising-spindle gate valves for isolating dust and ash handling lines.
Spring Support & Hanger
Variable and constant spring supports, rigid hangers and sliding supports for ductwork.
Best sellers
Products most often specified
FGD Flue Gas Damper Gate
Louvre-type gate for flue gas desulfurization systems, supplied as single-blade or zero-leak double-blade with sealing air.
Electric Double-Shaft Flue Duct Damper
Two parallel blade shafts linked by tie rods, driven by electric actuators — built for very large rectangular flue sections.
Regulating Damper Air Door
Linear-characteristic regulating damper for cold and hot air ducts, with ball-jointed linkage and no lost motion.
Double-Shaft Round Damper Gate
Circular double-shaft gate for large diameter flue ducts, with bolted flange mounting and linked blade banks.
Square Multi-Blade Air Damper
Rectangular multi-blade damper for combustion air, secondary air and flue ducts, with opposed or parallel blades and a linkage set in the works.
Guillotine Isolation Gate
A single plate that drops into the gas path to give a visible physical break, used for maintenance isolation on flue ducts where a louvre gate cannot guarantee a seal.
Light-Duty Flap Gate
A hinged single-leaf gate for low-pressure air and dust-laden gas lines, opened by the flow itself or by a small actuator, with a gravity or counterweight closing action.
Abrasion-Resistant Coal Gate
Heavy slide gate for coal bunkers, feeders and pulverizer outlets, with a hardened wear liner and a self-cleaning seat that clears coal dust on every stroke.
Compact Blade Damper Valve
A short-face, single-blade valve for tight shut-off on small and medium ducts, sized to fit between existing flanges without modifying the duct run.
Saddle-Seat Slide Gate Valve
A slide gate with a saddle-shaped seat that keeps contact pressure even across the full width, used on dust-laden ducts where a flat seat would wear unevenly.
Zero-Leak Isolation Valve
Double-seated isolation valve with a sealed cavity between the seats, used where a single seat cannot be trusted to protect a man or a catalyst bed.
Duct-Type Gate Valve
Rising-spindle gate valve for isolating dust and ash handling lines, with a through-conduit body that leaves no pocket for material to pack into.
Variable Spring Support & Hanger
Variable spring supports and rigid hangers for ductwork and pipework, selected from a standard range and supplied with the load and travel marked on the housing.
How to choose a damper gate
Three questions decide almost every selection: what is on each side of the gate, how tight does it have to be, and how often will it move.
1. What is the duty position?
Raw gas, clean gas, bypass and air duct positions see different temperature, dust and corrosion loads. A gate that is right for the air preheater outlet is usually wrong for the FGD clean gas outlet.
2. How tight is tight enough?
A single louvre gate gives around 90 % sealing. Zero-leak duty needs a double louvre with sealing air, which brings a fan set and a differential pressure monitor with it. Paying for sealing air where 90 % is adequate is as much a mistake as the reverse.
3. How often does it move?
A gate that moves twice a year can be specified on strength and seal alone. A gate in a control loop needs a linear characteristic, a ball-jointed linkage and limit switches set in the works.