单项选择题
A.protect the pump from fine soluble contaminants B.prevent solid particles from entering the pump C.prevent solid particles from entering the filter D.protect the directional control valves
On which of the following heated surfaces of a flash ty...
单项选择题On which of the following heated surfaces of a flash type evaporator would you be more likely to find soft scale formation?（）
A.Feed-water heater internal tube surfaces B.Internal distillate cooler tubes C.Flash chamber vertical surfaces D.Distilling condenser tubes
Machinery operating features are designed to help conse...
单项选择题Machinery operating features are designed to help conserve energy.Which of the following results will not contribute to energy conservation?（）
A.Reduction of friction B.Insulation of hot surfaces C.Lubrication of moving parts D.Elevation of cooler outlet temperatures
A refrigerant with oil in solution has a （）.A.higher bo...
单项选择题A refrigerant with oil in solution has a （）.
A.higher boiling temperature for a given pressure than does a pure refrigerant B.lower boiling temperature for a given pressure than does a pure refrigerant C.boiling pressure equal to that of a pure refrigerant at a given pressure D.boiling point will not be affected by entrained oil
