CleaverBrooks CBLE, Operation And Maintenance Manual

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Inspection and Maintenance
8-32 750-91 (revised 2009)
Model CB-LE Packaged Boiler Manual
Therefore, before assuming that the refractory requires reworking:
1. Check the condition of the tadpole gasket.
2. Check for cracks in the castable refractory.
3. Check the tightness of the door bolts.
4. See that the air line to the sight tube is clear, and that the connections are tight. If necessary, blow the line clear
with an air hose.
It is normal for refractories exposed to hot gases to develop thin “hairline” cracks. It by no means indicates improper
design or workmanship. Since refractory materials expand and contract with changes in temperature, they should be
expected to show minor cracks due to contraction when examined at low temperatures. Cracks to approximately 1/
8" across may be expected to close at high temperature. If there are any cracks that are relatively large (1/8" to 1/4"
in width), clean and fill them with high-temperature-bonding mortar.
If the refractory or blanket insulation require replacement, contact your local Cleaver-Brooks authorized
representative.
A good seal between the rear door and the pressure vessel is necessary to prevent leakage of combustion gases, loss
of heat, and to aid in obtaining operating efficiency. Leaks can also cause hot spots that can lead to premature
refractory failure and/or damage to the door metal.
Figure 8-16 Rear door seal
1. Tadpole gasket
2. Rope 1-1/2” dia.
3. Blanket insulation 1/2” x 2”