Waterside scale in a fire-tube boiler may cause （）.

[单选题]Fusible plugs are installed in fire-tube boilers to （）.A . provide a means of draining the boilerB . warn the engineer of low water levelC . cool the crown sheet at high firing ratesD . open the burners electrical firing circuit

[填空题] （）接头用于Tube管和Tube管之间的连接。

[单选题]H．ow to operate boiler?

[单选题]tube表示中文（）。A . 管子B . 圆棒C . 线材

[单选题]F．ire dampers prevent the fire spreading through the process ofA．convectionB．conductionC．radiationD．direct contact

[单选题]The water in an auxiliary boiler should be tested for chloride content to determine ( ).A．total dissolved solidsB．salt contaminationC．water harcnessD．chlorine contamination

[单选题]When an auxiliary boiler is panting and emitting black smoke, you should （）.A . increase the fuel oil temperatureB . decrease the fuel oil temperatureC . decrease the fuel oil supply pressureD . increase the air supply

[单选题]The water in an auxiliary boiler should be tested for chloride content to determine （）.A . total dissolved solidsB . salt contaminationC . water hardnessD . chlorine contaminatio

[单选题]If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.A . high steam pressure in the boilerB . abnormally high feed water temperatureC . abnormally high boiler water temperatureD . steam demand exc

[单选题]The boiler parameters should match with that of ( ).A.the generatorB.the st