Engineering · Steam — Water Treatment
Scale forming on the inside of boiler tubes is harmful because it:
- AImproves heat transfer
- BInsulates the metal, causing overheating and possible tube failure✓ Correct
- CIncreases steam purity
- DLowers the boiler pressure
Explanation
Scale (hardness deposits) is a poor conductor; it insulates tube metal from the cooling water so the metal overheats and can blister or rupture. Treatment keeps hardness in suspension.
Authority: Steam Plants (USCG engineering topic)
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