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How a National Paper Producer Uses Forney’s HRSG Bypass ‘Zero Leak’ Damper to Reduce Costs

Bypass Dampers are designed to ensure the correct gas flow in various exhaust systems. 

For Heat Recovery Steam Generators (HSRG), bypass dampers are essential for maintaining complete command of plant operations, particularly for planned shutdowns. It is also an effective tool when it comes to controlling the level of NOx emissions within state and federal regulatory limits.

In most HRSG power plants, bypass dampers used are either the guillotine or flap damper arrangement. Guillotine dampers are designed for optimal gas flow isolation, while flap dampers are great for diverting gas flow. 

While these two bypass damper arrangements are extremely effective at their particular HRSG support functions, these solutions are still lacking in one of the most important aspects of the heat recovery steam generation process: flow modulation and control.

To address the pressing problems inherent in most bypass damper designs, Forney developed a better, faster, and cheaper alternative to the usual bypass damper arrangements:

The HRSG Bypass ‘Zero Leak’ Damper


Forney’s HRSG Bypass ‘Zero Leak’ Damper utilizes two BiPlane dampers for superior isolation and control. The two BiPlane dampers allow for soft start and better control capabilities with an independent actuator on each damper. This allows the flue gas to enter the HRSG with a more evenly distributed flow pattern and at lower controlled flow rates than competing designs.

With one damper focused on the inlet to the HRSG and the other damper focused on isolating the stack, this creative damper combination makes all of these HRSG performance advantages possible:

  • Better soft start flow distribution
  • Better control capability
  • Better sealing performance
  • Faster time to open
  • Eliminated need for guillotine dampers
  • Smaller actuator requirements

Even better, the HRSG Bypass ‘Zero Leak’ Damper uses a safety system based on a mechanical interlock that prevents both dampers from closing at the same time while still allowing both dampers to remain open simultaneously. Its seal air system makes it easier for operational teams to identify and repair leaks quickly if they occur. 

Furthermore, the ‘Zero Leak’ Damper utilizes a dual set of seals, providing two layers of protection for HRSG personnel. 

Forney’s HRSG Bypass ‘Zero Leak’ Damper 

With all of the HRSG performance advantages offered by the Bypass ‘Zero Leak’ Damper,  a well-known global corporation enlisted Forney to create a convenient solution for their paper production process. 

This company produces thousands of products in the paper, health and beauty, and home goods space. As part of their manufacturing process, they use their HRSG’s process steam to make paper products with the goal of using 100% of the produced heat to support their paper production process while minimizing costs. This ensures a seamless application of economies of scale and maximizes paper production output. Any heat that escapes from the process is basically money lost. 

Before coming to Forney, the client was using an isolation damper similar to a guillotine damper for their HRSG. To effectively address their need to retain as close to 100% of the heat as possible, Forney provided its HRSG Bypass ‘Zero Leak’ Damper to work in conjunction with an isolation damper, essentially forming a duct tee of total control. 

While the HRSG Bypass ‘Zero Leak’ Damper can effectively hold all of the heat on its own, a coordinated effort with the isolation damper lessens the strain on both dampers, ensuring longevity and reducing the need for maintenance and repairs. 

When steam is needed for the paper production process, the isolation damper is opened and Forney’s HRSG Bypass Damper is closed, holding all of the heat in using the seal air fan. This produces a higher pressure of air than the turbine pressure, which effectively creates a solid curtain of air and efficiently prevents any heat from escaping.

With this combination, the client achieved their goal of utilizing all of the heat produced by their HRSG and minimizing operational and production costs.

HRSG Bypass ‘Zero Leak’ Damper Project Specifications

  • Size” 96” x 96” x 38” Face to Face
  • 6” of ceramic fiber 8lbs. density insulation
  • 304 stainless steel liner
  • 17-4ph High Strength stainless steel shaft
  • Bettis pneumatic actuator with a Fisher positioner
  • New York Blower 30 h.p seal air fan

Eager to experience the benefits of the HRSG “Zero Leak” Bypass Damper?

Forney’s “Zero Leak” Bypass Damper is the product of combining engineering principles, creativity, and innovative technologies. 

Our desire to help plants all over the world achieve maximum output at the highest efficiency levels continues to drive us to come up with reliable long-term plant operation solutions—and we can deliver the same level of attention and service to your company as well.

Contact your local Forney representative today to discuss your plant’s goals so we can provide you with a convenient and effective solution. 

About Forney

Forney Corporation has over 93 years of experience manufacturing the safest and most reliable combustion equipment for more than 1,000 power plants in more than 100 countries. The quality and durability of Forney’s state-of-the-art front-end combustion components have been proven by customers in many industries across the globe. Forney igniters, burners, BMS, flame detectors, dampers, and duct burners have provided efficiencies and cost savings for plant operators in electric utilities, chemical processing, pulp & paper, and cement industries.