A.to raise water level
B.only while making steam
C.to remove scum
D.when fire are secured
您可能感興趣的試卷
你可能感興趣的試題
A.drop as the boiler warms up
B.rise as the boiler warms up
C.remain unchanged until the boiler is hot enough
D.rise and fall with the steam demand
A.filled with water
B.purged
C.cleared of air
D.None of the above is true
A.Safety valves
B.Water tubes
C.Steam stop valves
D.Blow down valves
A.water-tube
B.fire-tube
C.exhaust gas
D.None of the above is true
A.water-tube
B.fire-tube
C.exhaust gas
D.none of the above
最新試題
A salinity indicator is used to determine the （）.
The major source of chemical contaminants in hydraulic fluid is （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
A pressure drop through the refrigerant liquid line may cause （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
The general purpose of a heat exchanger is to （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.