25 May 2005
Start-up of New Boilers and Condensate Systems or Repaired
. As a result
of the fabrication process,
a new or repaired boiler that
the field or shipped as a package unit will likely contain oils and greasy films, and
perhaps rust, on the metal surfaces. The oils, grease, and rust can contribute to
carryover and contaminate the steam and initiate corrosion of the boiler components. A
pre-operational alkaline boil-out procedure is required to remove these materials. This
pre-operational process is usually part of a new construction project and therefore may
not be in the direct control of boiler operations personnel. Often, the contracting officer
involved with the project can provide verification of the completion of this important step.
The following example of an alkaline boil-out procedure consists of four steps:
1. Inspect the inside of the boiler and remove all debris.
2. Add an alkaline boil-out chemical formulation to the boiler water. This
should be roughly equivalent to the following formulation: 10.4 kilograms
(24 pounds) of caustic soda, 10.4 kilograms (24 pounds) of disodium
phosphate, 3.5 kilograms (8 pounds) of sodium nitrate, 0.2 kilogram (0.5
pound) non-ionic wetting agent (a low-foaming detergent) per each 3785
liters (1000 gallons) of boiler capacity.
3. Fill the boiler to the steam header and maintain at low fire for 1 to 2 days.
For condensate systems, this formulation should be circulated for 3 to 4
days, drained completely, and the system dried completely by purging with
4. Drain and flush. Proceed immediately to operational treatment levels or to
a layup status. Untreated water should never be allowed to remain in the