Parker Fabrication Inc.

Special Items

Featured Item - Rain Caps


Parker Fabrication is pleased to now offer an improved design rain cap.  Through customer feedback and engineering research, the new rain cap design offers multiple improvements over the previous design and competitor's product.  The rain caps were optimized for durability, smaller packaging size, corrosion resistance, and lower cost.  Review the Sales Presentation for and in depth analysis of the improved features. 

Please contact our Sales or Engineering Departments for more details.


New Rain Cap Design Features


Soliciting feedback from multiple customers, it was determined that the following improvements were desired from the Parker Fabrication current rain cap design and from competitor rain caps:


  • Greater resistance to corrosion that can cause the cap to stick open or loose function
    • This issue was addressed by coating with high temperature (1200 degree) wet paint, stainless steel pivot rod, and brass bushings to the new design.
  • Increased durability that would allow the rain cap to withstand a larger backfire from the engine without deformation that could lead to binding or separation from the stack
    • The new design used extensive finite element analysis to optimize the strength of each component while minimizing the rotating mass of the assembly.  The lower rotating mass along with a greater opening angle reduces the impact force during a backfire event when the cap reaches the mechanical stop.  The lower impact force reduces the chance of lid deformation causing loss of function or cap separation from the stack.
  • Reduced back pressure and vertical flow from the cap (no eddy currents or back flow down stack)
    • The back pressure and flow concerns were address by increasing the lid opening angle.  Optimization of the kinematic geometry allows for an 80 deg opening angle, but with a normalized shutting force.  All basic caps are designed with a 2" H2O lift off force, and less than 1" of H2O running back pressure at rated speed.  The larger opening angle also prevents eddy currents or back flow events down the stack.
  • Smaller overall size, profile, and rotating envelope to aid in packaging and shipping
    • The new design has a significantly small packaging envelope.  The counter weight never travels below the clamp band.  Improved packaging envelope specifications are available upon request.

18 inch rain cap

Send us your questions




Industrial Exhaust Rain CapsExhaust Rain CapsReverse Engineering PeoriaMarine ExhaustStructural BendingTube End Forming PeoriaTube SwagingPrototype FabricationIndustrial Rain CapsTubing ElbowsMandrel BendingExpansion JointsExhaust Flanges PeoriaMandrel Bending or Mandrel Tube BendingROPS and FOPSDiesel Engine Exhaust PeoriaGenerator Exhaust PeoriaDiesel Exhaust Emissions PeoriaExhaust Bellows PeoriaTube Swaging PeoriaTube Fabrication PeoriaFlexible Exhaust PeoriaPipe Fabrication PeoriaMandrel Bending PeoriaIndustrial, Marine, Diesel Engine, and Generator ExhaustsDiesel Exhaust Emissions and RICE NESHAPLarge Tube Bending, CNC Tube Bending, and Structural Steel BendingSquare Tube Bending and Steel Tube BendingBellows and Expansion Joints Pipe Fabrication