A.worn gland sealing shaft
B.worn wearing rings
C.a bent shaft
D.reversed pump coupling
您可能感興趣的試卷
你可能感興趣的試題
A.A power end and fluid end
B.A propeller and educator
C.A volute and impeller
D.A turbine and piston
A.water seal pipe is plugged
B.pump is not primed
C.seal ring is improperly located
D.impeller is flooded
A.Close radial clearance between impeller hub and casing
B.Low rotational speed of impeller
C.Removable end plate
D.Replaceable impeller and casing wearing rings
A.fill the unit with saltwater
B.fill the unit with de-scaling compound
C.completely drain the unit
D.tightly seal the unit to exclude air
A.dischargeendbeingsmallerthanthesuctionend
B.smallsizeofimpeller
C.lackofmovingparts
D.easeatwhichthewearingringsmaybechanged
最新試題
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
Which of the listed pumps is NOT a positive displacement pump?（）
Low compressor head pressure in a refrigeration system can be caused by（）.
The general purpose of a heat exchanger is to （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）