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References: Damper Details and Duct Connections

  1. Butterfly valve - Wikipedia - Describes the rotating-disc butterfly valve and its wafer-style body that clamps between pipe flanges, the same construction as the blast gate on pressure blower outlets in this chapter.

  2. Expansion joint - Wikipedia - Covers flexible joints, including fabric expansion joints for ducts, that absorb movement and vibration. Background for the chapter's flexible connectors and slip connections on isolated fans.

  3. Euler's pump and turbine equation - Wikipedia - Derives the turbomachinery work equation from angular momentum with velocity triangles, the equation the chapter uses to explain why inlet pre-spin reduces impeller work.

  4. Fluid Mechanics and Thermodynamics of Turbomachinery (7th ed.) - S. L. Dixon and C. A. Hall - Butterworth-Heinemann - Dixon's velocity-triangle treatment of the Euler work equation is a standard teaching route for showing how inlet prewhirl from guide vanes lowers the work an impeller does.

  5. Industrial Ventilation: A Manual of Recommended Practice for Design (30th ed.) - American Conference of Governmental Industrial Hygienists (ACGIH) - Widely used for its blast gate balancing method and system design procedures, the practice context for blast gates and duct connections.

  6. FanPedia: The Fan & Blower Encyclopedia (PDF) - Twin City Fan - Primary source for gravity, industrial and lab exhaust dampers, blast and slide gates, inlet vanes, inlet box styles, flexible connectors and tube adapters.

  7. FanPedia online - Twin City Fan - Web edition of FanPedia with Accessories galleries for dampers, inlet boxes and connections, useful for identifying the damper and connection styles in this chapter.

  8. Fan Damper Selection (FE-2600) - Twin City Fan Engineering Letter - Discusses gravity and motor-operated dampers, blade flutter at low flow, blade types and inlet box dampers that pre-swirl air, expanding the chapter's damper detail.

  9. Vibration Isolation of Fans (FE-1900) - Twin City Fan Engineering Letter - States that isolated equipment must be flexibly connected to its ductwork, since rigid duct short-circuits the isolators, the rule behind the chapter's flexible connector requirement.

  10. ASME B16.1 Gray Iron Pipe Flanges and Flanged Fittings - ASME - Current standard for Class 125 cast iron pipe flanges, the successor to the ASA pattern that the blast gate and tube adapter bolt to.