Overheat and corrosion are common HRSG viewport problems. Additionally window size and internal moving parts can block views of the duct burner flames. Original viewport locations also may not be optimized for viewing burner elements and the downstream tubes. As a result of viewport issues, Duct burner mechanical problems and flame shape/length problems may go undetected causing overheat damage and unplanned maintenance. Click here to request HRST CoolVision™ Vewport and HRST Firing Duct Video Camera System Brochures: Brochure Request

Upgrade to CoolVision™ Firing Duct Viewport

HRST’s patented (US Patent #11603992) dual pane viewport design utilizes a three piece frame assembly with dual panes of glass and layers of insulating gaskets to reduce the heat transfer from the firing duct to the outer window pane, frame and the adjacent HRSG casing. Because there are no moving parts, the viewport allows “walk up and look” viewing. The stainless steel 304 housing and optional stainless steel 310 inner frame allow use in almost all HRSG firing duct applications. HRST can evaluate and supply, if needed, the inner flashing and casing modifications to optimize the viewport location for operator friendly viewing.

Benefits of HRST CoolVision™ Firing Duct Viewport:

  • Design reduces heat transfer to outer casing

  • No cooling air required for most arrangements

  • No moving parts to get stuck and block views

  • Window size (6” x 9”) can allow better field of view compared to original viewports

Email us now to learn more about the HRST CoolVision™ Firing Duct Viewport!

The following thermal images show a comparison of temperatures recorded on a 15+ year old original viewport (left) and a HRST CoolVision™ Firing Duct Viewport (right).

CoolVision™ DR Viewport

Retrofit your existing viewports with HRST’s CoolVision™ DR (Direct Replacement) Viewport for a bigger viewing window and reduced heat transfer. We can supply direct replacements for:

  • Tate Jones (DR-T)

  • Vogt (DR-V)

  • John Zink (DR-J)

  • Zeeco (DR-Z) viewports.


  • Uses same bolt arrangement as most Tate Jones, Vogt, John Zink, and Zeeco viewports

    • No welding required

  • No Technical Advisor required (unless requested by customer)

HRST Firing Duct Video Camera System

Avoid firing duct and tube overheat damage with better flame monitoring! If visual checks of flame patterns and burner conditions are not performed, expensive downstream damage can occur. HRST offers a complete system package: camera and mounting hardware, casing wall box and internal liner flashings, and wireless transmitters.

Benefits of HRST Firing Duct Video Camera System:

  • Continuous view of burner and flame appearance in control room

  • Identify changes in flame appearance quickly before downstream damage is done

  • Wireless feed of camera signal to dedicated control room monitors