Prepared by the Air and Gas Duct Structural Design Committee of the Energy Division of ASCE.

Structural Design of Air and Gas Ducts for Power Stations and Industrial Boiler Applications, Second Edition, assists structural engineers in the layout and performance of the structural analysis and design of air and flue gas ductwork for natural gas, coal, oil, reciprocating internal combustion engines (RICE), and all other fossil fuel power stations and industrial boiler applications. Air and flue gas ducts are unique structures, yet the structural analysis and design of ductwork is not currently addressed or governed by any national code or design standard.

Topics include:

• Flow, damper, and expansion joint ductwork arrangement considerations and impacts on the structural design;
• Material selection, behavior, and performance of carbon steel, stainless steel, and alloys for elevated temperatures and in corrosive environments including creep rupture, temper embrittlement, and graphitization phenomena;
• Air and flue gas ductwork unique loading cases and means of considering these loads in ASD and LRFD load combinations;
• Truss and finite element structural analysis modeling techniques;
• Strength design methods incorporating the AISC stability requirements (P-delta impacts);
• Longitudinal, tangential, and hoop stress considerations for the design of circular ductwork;
• Thermal and vibration considerations including thermal gradients and vortex shedding of internal elements;
• Thermal insulation systems;
• Toggle duct behavior and expansion joint considerations; and
• Structural assessment and reinforcement of ductwork as a result of changing operating conditions or ductwork modification.

This fully updated report also discusses drawing and specification content, fabrication and construction techniques and considerations, duct support means, and special considerations regarding the design of duct support structures. Preventative maintenance examinations and inspections for the purpose of condition assessment and ascertaining the structural integrity of the ducts also are discussed.

This new edition will be a valuable tool for structural engineers to understand the structural behavior of a duct system and in analyzing and designing its many structural components.