HOW AUGUSTA FIBERGLASS MET ONE CUSTOMER’S NEED FOR DUCT UNDER DIFFICULT CONDITIONS
This large turnkey project required Augusta Fiberglass to demolish existing metal duct and replace all of the saddles and duct work within a tightly set time frame. The replacement Fiberglass Reinforced Plastic Duct would be fabricated in sections 16 to 20 feet in diameter. Fabricating the duct at the power plant site was considered, but found not to be feasible.
The first challenge in this project was to remove the deteriorated metal duct from the plant. By using a qualified subcontractor whom Augusta supervised, the existing metal duct and saddles were removed. Complicated steel replacement saddles were designed by Augusta Engineers a and fabricated by one of Augusta’s quality metal fabrication approved vendors.
Augusta Fiberglass and its Sister Companies AFC South and B&D Plastics teamed up to produce the Duct sections, elbows and expansion joints at their Blackville, SC and Ocean Springs, MISS facilities
To meet the deadline and to overcome the problems of transportation created by the size of the duct sections, Augusta Fiberglass transported the sections to the B&D privately owned dock to be loaded onto ocean going barges
Once at the dock the Duct sections were loaded onto ocean going barges for transport to the job site in Florida.
To design the duct sections and other elements, Augusta Fiberglass brought its full engineering skills into play including calculations using finite element analysis.
Duct with Elbow The plot shows analysis of FRP duct with rectangular to round transitions, miter elbow, eccentric reducer, eccentric “Tee”, steel anchor and sliding saddle, turning vanes and eccentric round to rectangle transition. The duct, saddle, slide bearing were designed for the project specification and ASTM D5364. The stiffness of the steel support structure was taken into consideration by using spring elements. The global analysis checked the strains for each layer in each direction with the project allowable, buckling factor of safety for wind pressure and design external pressure, the stress and deflection in transition steel and FRP transition panel, saddle reactions, force at the duct joints and FRP flange deflection for the sizing of Expansion Joints. Local analysis was conducted to analyze steel anchor and sliding saddles, FRP joints, anchor shoulder, turning vanes, transition steel and slide bearing.
The quality control officers were on hand throughout the project to ensure that every section of duct, every elbow, every transition joint met each and every standard.
OUTCOME
Here is what part of the job looked like when Augusta was finished, on time and without accident.
