Stack Dampers

DTL Stack dampers are designed to minimise heat loss from your boiler and to prevent the ingress of rain water. Our stack isolating dampers are bespoke so can be designed for use with any exhaust stack in the range of 300mm – 8000mm Diameter.

A stack damper can be supplied as either a butterfly or multilouvre design and will typically incorporate an automatic pressure relieving system which opens the blades in the event of unexpected pressure spikes. Opening the blades therefore prevents over pressurisation and subsequent damage to the HRSG and gas turbine.

An optional drain channel built into the central beam of the framework provides weather protection by channelling rain water from the blades out to a dedicated drain point on the side of the damper, therefore protecting the boiler.

DTL Stack Dampers are also referred to as a Weather Protection Damper or Rain Dampers are generally manufactured in Carbon Steel or Stainless steel. However, for special applications we can utilise any material to suit your requirements such as 800HT, 310S, Alloy 31, Alloy 59…

Our stack dampers are often supplied with electric actuation, but can also be provided with pneumatic or manual operating systems. All actuation systems are flexible so can be supplied to operate locally, remotely, or from floor level.

Stack damper

Additional Images:

Interesting in finding out more? Request a Brochure.

Typical Applications

  • Exhaust Stacks

Stack Damper Specifications

Technical Specifications

  • Pressure: Typically 50Kpa (0.5 barG) Higher on request
  • Temperature: Typically 600°C (1112°F) up to 1250°C (2282°F) on request


  • Round or rectangular design
  • Fully welded body
  • Specially engineered for a compact design
  • On/off or modulating
  • Pressure relieving
  • Typical range from DN300 to DN8000 (other sizes available on request)
  • Electrically actuated (Pneumatic actuators also available on request)

Optional Extras

  • Pneumatic cabinet
  • Maintenance free bearings
  • Rain Channels
  • End connections: Flanged to fit ANSI, EN, JIS standards

Interesting in finding out more? Request a callback.

Get in Touch