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Specialty Custom Solutions

 EPIC® HRSG Off-line Cleaning

Advanced HRSG off-line cleaning technology that removes deposits safely and effectively.

Services > Specialty Custom Solutions > EPIC® HRSG Off-Line Cleaning



EPIC® HRSG Off-line Cleaning

The EPIC® Extraction Pressure Impulse Cleaner is revolutionizing HRSG cleaning. This off-line cleaning technology uses safe, effective and directly targeted impulse cleaning energy to remove deposits deep within and throughout tube bundles. The patent-pending cleaning procedure that is employed systematically concentrates its affect just to the fouled tube sections, with no indiscriminate blasting impact to the surrounding area, nor mechanical fatigue to the tubes or superstructure.

This type of cleaning system has been used effectively for over a decade for on-line boiler cleaning including HRSGs. IMPULSE® pressure waves are generated in a controlled, pulsed manner, safely within a 3-inch system chamber to direct cleaning waves into surfaces where debris has collected. EPIC® utilizes pressure waves to create a high amplitude particle displacement to resonate and dislodge particulate deposits. This creates a very targeted, deep 360° cleaning so heat transfer efficiency can be restored.

Read the case study below to learn how combined-cycle facilities are regaining 3-6 inches of pressure drop and improving their bottom line by $600,000 or more annually.


Safely and cost-effectively mitigate dust.


  Targeted impulses create deep, penetrating + encompassing 360°cleaning

  No mechanical integrity damage to tubes or entire structure

  No mechanical tube stretching or spreading required Energy is directionally controlled through the tube bundle (i.e. no violent shock or indiscriminate blast impact to entire HRSG structure)

  No scaffolding required

  Reduced outage time compared to alternative methods

 Proven on-line cleaning technology for 10+ years supported by multiple US patents

Case Study


A large combined cycle utility plant in the SE was experiencing substantially reduced efficiency and performance from their HRSG due to the insulating and CT back pressure effects from excessive deposits on and deep within the finned tube bundles. Prior cleanings performed, typically every other year, had not been sufficiently effective.



The plant researched multiple options to achieve a more effective and penetrating means to clean all their bundles downstream of the SCR and selected the patented EPIC technology that safely utilizes a series of repeated and concentrated dynamic shockwave cleaning impulses directly and deeply into the tube bank. The cleaning is coordinated via a remotely controlled navigation system with all personnel located safely outside of the HRSG unit.

Several unique features include:

  • Real time visual observation from 6 camera positions monitored within the ground level command center module.
  • Progressive back pressure reduction of each segment, as its being cleaned, is also captured and trended in the control module.
  • Before and after borescope videos proved the visual results
  • Multiple pneumatic vibrators used as subtle additional motivation of dislodged material to drop to grade level for its removal


The EPIC™ cleaning system effectively dislodged and removed the deep and heavily impacted deposits that had accumulated on and within the finned tube surfaces as evidenced by post-cleaning visual inspection throughout the HRSG by videoing into multiple harp panels by borescope. The operating performance was later evaluated by plant personnel reporting the combustion turbine back pressure was reduced by 4 inches of water column, resulting in a heat rate decrease by roughly 0.5 MMBtu/MWh. This was computed to yield an equivalent payback in 1,018 hours (41 days) due to increased efficiency and reduced fuel costs, based on a 100% production (MW) load.

Reduced outage time compared to alternative methods

Why EPIC Over Other Methods

Safe for Your Entire Unit

EPIC’s impulses are highly targeted through the tube bundle and do not cause any damage to the mechanical integrity of the tubes. Plus, there is no violent shock or indiscriminate blast impact to the HRSG structure. In addition, the tubes will never be stretched or spread.


No Pre-Cleaning Work

No scaffolding is required nor tube spreading, or other modifications are necessary to gain access for cleaning. Minimal site support resources are needed.


Reduced Cleaning Time

Utilizing the advanced EPIC technology, with remote positioning and activation of the IMPULSE cleaning equipment, results in reduced overall outage duration as well as confined space exposure compared to several other methods. The service is also complemented by the post-cleaning removal of the considerable dislodged debrisby incorporating Thompson’s own vacuuming equipment and personnel, rather than orchestrating additional arrangements with yet another contractor for the turnkey HRSG cleaning project.

EPIC™ and IMPULSE® are the property of PowerPlus Cleaning Systems, Inc. Thompson Industrial Services, with over 30 years of cleaning experience, proudly executes the EPIC technology in the field.



EPIC HRSG Pressure Wave Cleaning Technology
EPIC HRSG Cleaning Technology Example Results
EPIC HRSG Off-line Cleaning Case Study

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