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單項選擇題

The forced draught fan should be started and air passed through the furnace for several minutes to “（）” it of any exhaust gas or oil vapors.

A.blow
B.clean
C.scavenge
D.purge

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單項選擇題

A shallow dish positioned at the normal water level is connected to the（）This enables the blowing down or removal of scum and impurities from the water surface.

A.main stern stop valve
B.auxiliary steam stop valve
C.scum valve
D.blow down valve

單項選擇題

The（）enables water to be blow down or emptied from the boilerIt may be used when partially or completely emptying the boiler.

A.main stem stop valve
B.auxiliary steam stop valve
C.feed check or control valve
D.blow down valve

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