25 May 2005
8. When the boiler is completely cool, add more water to ensure it is full.
Maintain a pressure of 35 to 69 kilopascals during layup and maintain the
levels of alkalinity and sulfite.
9. Inspect the boiler on a regular basis and replace any water losses. To
facilitate inspections, a small steel tank equipped with a gauge glass can
be installed above the top of the boiler, as shown in Figure 3-15. Fill the
tank with treated water and connect to a steam takeoff tap, vent, or safety
valve connection. A glance at the water level in the small drum will quickly
tell whether or not the boiler is completely filled.
Figure 3-15. Inspection Gauge for Wet Boiler Layup
Boiler Steam Drum
Layup of Condensate Systems. Layup of condensate systems is much
more difficult than layup of boilers. As the system cools, oxygen will be drawn in,
resulting in a situation that leads to corrosion. Purging the system with dry, inert gas can
be effective, but the logistics can be nearly impossible and the hazards include the
potential for suffocating people if the system is located in an unvented area. Application
of a high dosage of a filming amine prior to shut down can be effective, but its use is
restricted for many applications and is prohibited in military operations. Application of a
high dosage of neutralizing amines (see paragraph 3-2.7.3) or of a specialty volatile
oxygen scavenger (see paragraph 3-2.7.5) can be helpful. The application of any amine
or specialty volatile oxygen scavenger can be limited where steam purity or FDA