Flowseal butterfly dampers are designed and fabricated to meet the requirements of power and industrial plants and to comply fully with the requirements of AMCA publication 850-84. They provide effective and reliable isolation and or control in hot, noxious, corrosive and dirty gas flow conditions.
Flowseal butterfly dampers are manufactured with two ply airofoil shape blades, without external ribbing or bracing, which provides smooth and laminar flow. The butterfly dampers can be manufactured circular or rectangular in shape. All butterfly dampers are fitted with spherical maintenance free bearings or maintenance free DU bushes which have proven most reliable in all conditions.
Flowseal butterfly dampers are designed for minimum maintenance, and that which is required is simple and can be performed while the system is on line.
Associated Terms:
- Gas Dampers
- Damper Valves
- Industrial Dampers
- Butterfly Dampers
- Circular Butterfly Dampers
- Rectangular Butterfly Dampers
- Single Bladed Dampers
- Double Bladed Dampers
- Opposed Acting dampers
- Isolation Dampers
- Shut off dampers
- Tight Shut off Dampers
- Flow Control Dampers
- Control Dampers
- Air Movement Equipment
- Flow Regulating Dampers
- Metal Seated Dampers
- Sealing Efficiency
- >95% Sealing Efficiency
- >98% Sealing Efficiency
- >99% Sealing Efficiency
- AMCA
- AMCA International
- Air Movement and Control Association International
CA Standards
The following styles of butterfly dampers are available:
Type CRS stainless steel flexible seal Butterfly Dampers?
Sealing efficiency : 99% of full flow or better.
Similar to the type STS described above except that blade edges are fitted with stainless steel flexible seals to improve the sealing efficiency of the damper.
Type CRS stainless steel flexible seal Butterfly Dampers?
Sealing efficiency : 99% of full flow or better.
Similar to the type STS described above except that blade edges are fitted with stainless steel flexible seals to improve the sealing efficiency of the damper.
General Design
Flowseal butterfly dampers can be fabricated for any duct size, circular or rectangular and can be fitted to a vertical duct or to a horizontal duct with the blade spindles vertical or horizontal.
The dampers are designed to fulfill specific application requirements and conform to the following Minimum Specifications.
Construction
Materials of construction are selected for their suitability for the conditions of temperature and pressure, and the corrosive and abrasive environment of the system.
Frames?
Frames are designed to be entirely self-supporting in the duct with no external mounting or anchoring required and are normally of the channel type, either welded or of a rolled structural section. The flanges are pre-drilled to customer requirements. The frames are designed for the system pressure and temperature as well as construction and transportation loadings.
Blades?
Damper blades are of double ply construction and aerofoil in shape. Stub shaft connections are adequately strengthened for the bolt fastenings. Damper blades are designed so that the maximum deflection under operating conditions does not exceed L/360.
Packing Glands?
Packing glands are continuously welded to the damper frame at each shaft clearance hole and are filled with packing suitable for ambient as well as operating conditions. The glands are designed in such a way that packing may be renewed without removal of bearings or linkages.
Live loaded packing gland seals are available for applications where maintenance is to be kept to a minimum.
Bearings?
Bearings are DU Bushes or of the spherical type, both types are maintenance free, under no circumstances will ball or roller bearings be considered due to their potential to brinell and seize under normal damper operating conditions. The bearings shall be located sufficiently removed from the heat source to ensure that they are operating within their design temperature rating.
Stub Shafts?
Stub shafts will always be manufactured in grade 304 stainless steel or better. The stub shafts are designed to transmit the maximum torque potential of the drive mechanism. All lever and actuator bushes and bosses are to be fitted with parallel keys.
It is imperative that the combined geometry of blade connection, thru gland seal, to outboard mounted bearing and lever arm or actuator connection, is such that the potential for pushing the shaft out of alignment during operation is totally eliminated.
Actuators?
Flowseal butterfly dampers can be furnished with electric, pneumatic, hydraulic or manual actuators. The actuators are sized to function reliably over the full range of system temperatures and pressures with a minimum factor of safety of two. Actuators may be fitted with positioners, I/P converters, solenoid valves, manual overrides and fail safe open or fail safe closed devices if required. All actuators are fitted at the factory and fully tested prior to shipment. Actuators can be fitted to either shaft and on either side of the Damper.