单项选择题

If the capacity of a centrifugal pump decreases gradually over a long period of time, you should replace the （）.

A.packing gland
B.mechanical seals
C.lantern rings
D.wearing rings

相关考题

Distilled water from an evaporator may be discharged in...

单项选择题Distilled water from an evaporator may be discharged into a potable water tank （）.

A.through a detachable hose connection
B.after passing through an activated charcoal filter
C.after chemical analysis shows it is fit for consumption
D.through a solenoid operated three-way valve

If a centrifugal pump vibrates and is noisy when operat...

单项选择题If a centrifugal pump vibrates and is noisy when operating, the cause could be （）.

A.worn gland sealing shaft
B.worn wearing rings
C.a bent shaft
D.reversed pump coupling

Which of the devices listed is common to all types of p...

单项选择题Which of the devices listed is common to all types of pumps?（）

A.A power end and fluid end
B.A propeller and educator
C.A volute and impeller
D.A turbine and piston

船舶辅助机械

If the capacity of a centrifugal pump decreases gradually over a long period of time, you should replace the （）.