无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

單項(xiàng)選擇題

Which action should be taken when an auxiliary boiler in is operation?（）

A.Clean all electrical connections
B.Lift the relief valves by hand
C.Inspect and clean all solenoid valves
D.Inspect for oil and water leaks

你可能感興趣的試題

單項(xiàng)選擇題

Ignition failure in an automatically controlled auxiliary boiler could be caused by（）

A.carbon deposits on the flame scanner
B.high fuel oil temperature
C.low fuel oil viscosity
D.high steam pressure

單項(xiàng)選擇題

Heavy soot accumulations in an auxiliary boiler could be caused by（）

A.water in the fuel oil
B.excessive cycling
C.high fuel oil pressure
D.improper burner maintenance

<pre id="jnird"><acronym id="jnird"></acronym></pre>