10 Heat Recovery Steam Generator Cleaning

Equipment inspections often require the HRSG sections to be drained and open. Performing inspections throughout the commissioning process is advised to ensure that debris is removed and deficiencies in waterside surfaces are detected and corrected. Inspections should include the following activities:

• Crawl-through visual inspection of waterside surfaces of all vessels (steam drum, condenser, makeup and condensate tanks, and deaerator, if installed). Cogeneration facilities may have additional vessels that require inspection.

• Videoscopic inspections of headers and a representative number of tubes in each accessible tube bundle. Individual HRSG sections should be inspected immediately before assembly to document the “as received” condition. This inspection will help identify waterlines and corrosion which may be present before assembly.

• Tube sampling. If the videoscopic inspections indicate the presence of significant deposits in the tubes, a tube sample may need to be collected to select an appropriate cleaning solvent.