单项选择题
Excessively low air pressure occurring in the intercooler of a reciprocating air compressor is caused by（）.
A.leaky discharge valves on the LP cylinder B.leaky discharge valves on the HP cylinder C.insufficient intercooler cooling D.low ambient air pressure
单项选择题 Most pump manufacturers recommended that the discharge piping for centrifugal pumps be （）.
单项选择题 If a refrigeration compressor is short cycling on high head pressure, you should （）.
单项选择题 What color is used to indicate the last shot of anchor chain?（）
