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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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單項選擇題

The（） is fitted in pair one is the main valve, the other the auxiliary or standby.

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

單項選擇題

The（） is a smaller valve fitted in the auxiliary steam supply line, and is usually of the non-return type.

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

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