Tried and true: Sammet’s louver and butterfly dampers
Sammet’s Product Group Manager Mr Jyrki Kuitunen is brimming with enthusiasm as he prepares to discuss the products he helps design and manufacture. Louver and butterfly dampers are Sammet’s most popular product groups, and commonly used in powerplants and by processing industries.
Kuitunen’s relationship with Sammet started during his engineering degree when he researched Sammet’s damper control systems for his thesis. The work was of such high quality, Kuitunen was offered a full-time position with Sammet. That was 20 years ago.
Just like Kuitunen, Sammet’s louver and butterfly dampers are a reliable and indispensable part of Sammet’s business. Kuitunen clearly enjoys his work and sharing his knowledge.
Tried and true products
He starts with the basics, explaining that a louver damper is rectangular in shape and a butterfly damper is round, but that the operating principles and mechanical properties are similar. The louver and butterfly dampers can have two functions: On/off (i.e. isolating) or control (i.e. regulating) gas and air flow. They are the most popular and established product groups, commonly used in powerplants and processing industries.
While the on/off damper blades sit parallel to each other, control damper blades turn towards each other and the flow is directed to the centre of the duct for better control. “The blades in the round control damper look like butterfly wings as they move around the central access, which is where the name comes from”, Kuitunen says with a smile. Butterfly dampers are used where flow control and low leakage isolation are a priority. These dampers are especially useful in applications such as Sammet’s world class designs for scrubber systems. A Finnish beer factory is one of the more interesting places to benefit from these Sammet dampers.
Meeting the diverse needs of customers worldwide
Any engineering parameters, such as materials and design, painting and project documentation can be tailored to specific customer needs. Damper sizes range from the smallest DN60 flap damper to an 8x8 meter on/off damper. Maximum tightness is 100% and the minimum tightness is always specified by the customer. Flow speed in ducts is typically between 15 to 25 m/s to prevent too much high-pressure loss. Other important specifications that can be tailored to customer needs include dimensions, pressure, temperature, actuator and accessories, surface treatment and materials. Some purifying plants have very abrasive particles in gas flow and Sammet uses special steels to manufacture the dampers to prevent unwanted wear and tear.