In most marine boilers, the primary reason the first few rows of generating tubes, called screen or furnace row tubes, are made larger in diameter than the rest of the generating tubes is because __________.

Correct Answer: Option A — they require more water flow since they are exposed to the greatest heat

In USCG Steam Plants (Boilers & Turbines), regarding 'In most marine boilers, the primary reason the first few rows of generating tubes, called screen or furnace row tubes, are made larger in diameter than the rest of the generating tubes is because', the verified engineering fact is: 'they require more water flow since they are exposed to the greatest heat'.