Excessive oil foaming in the crankcase of a refrigeration compressor at start up can cause（）.

Foaming in the steam drum may be caused by （） in a boiler.

Foaming of the oil in a refrigeration compressor crankcase is caused by （）.

A condition that can increase the foaming tendency of lube oil is （）

In a refrigeration system, foaming of the crankcase oil may cause the （）.

Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor.

A condition that can increase the foaming tendency of lube oil is （）

Excessive oil foaming in the crankcase of a refrigeration compressor can result in （）.

Foaming in the steam drum may be caused by （） in a boiler.

Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor.