Comprehesive Boiler Manual Jan 2019

3) Small Boiler Layup/Seasonal Down
Seasonal Shutdown
i. Wet
WET ii. Dry LAYUP
Two to seven days before a wet layup, water chemistry should be
increased to the following levels:
• 200 to 400 PPM sulfite
Steel Boilers < 30 days and Cast-Iron Sectionals
• 600 to 800 ppm hydroxide alkalinity
• Scale/corrosion inhibitor in normal ranges for on-line operations
• Periodically check water level for leaks
DRY LAYUP
Steel Boilers > 30 days
days
• Drain and mechanically dry inside of boiler to prevent stagnant water corrosion (rust).
• A moisture absorbing material, such as quicklime (2 #s/30 ft³) or silica gel (5 #s/30 ft³ of
boiler volume) may be placed on trays inside the drums to absorb residual moisture from the
air.
• Use Humidity Cards to confirm internals are dry.
• Check Humidity Cards monthly during shutdown.
Dessicants can be reused by drying between
seasons. Simply warm dessicant to 200˚F for 1
hour to expel any moisture.
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