The tube in a boiler should be blinded if found _____.A.scaledB.informedC.leakyD.deformed

Which of the following may hardness of the boiler water cause？ （1) scale formation; （2) tube failure; （3) corrosion.

Failure of the burner flame in an auxiliary boiler would probably be a result of .A.water

In a （) boiler the water flows through the inside of the tubes while the hotgases pass ro

Too much air in the furnace of an oil－fired boiler would be indicated by _____.A.yellowish

If in doubt as to the true water level when a boiler is being oil－fired, you should _____.

Generating tubes in waste heat boilers are finned to _____.A.reduce gas flow turbulenceB.p