7/23/2019 Centrifugal Pumps Trouble Shooting

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Centrifugal pumps trouble shooting

TROUBLE CAUSE

Does not deliver

any liquid

Insufficient priming liquid

Insufficient pump speed

Excessive discharge pressure (such as a partially closed valve

or some other obstruction in the discharge line)

Excessive suction lift Clogged impeller passages

Wrong direction of rotation

Clogged suction screen (if used)

Ruptured suction line

Loss of suction pressure

Insufficient

capacity

Cracklin noise

fro! t"e pu!p

casin

 ir lea!age into the suction line

Insufficient speed of the pump

Excessive suction lift

Clogged impeller passages

Excessive discharge pressure

"echanical defects (such as #orn #earing rings$ impellers$

stuffing box pac!ing$or sleeves)

Does not develop

enou" disc"are

pressure

Insufficient speed of the pump

 ir or gas in the liquid being pumped

"echanical defects (such as #orn #earing rings$ impellers$

lea!ing mechanical seals$ and sleeves)

#orks for a $"ile

and t"en fails to

 ir lea!age into the suction line

 ir lea!age in the stuffing boxes

7/23/2019 Centrifugal Pumps Trouble Shooting

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deliver liquid Clogged #ater seal passages

Insufficient liquid on the suction side

Excessive heat in the liquid being pumped

Takes too !uc"

po$er and t"e

!otor over"eats

%peration of the pump at excess capacity and insufficient

discharge pressure

"isalignment

&ent shaft

Excessively tight stuffing box pac!ing

Worn #earing rings

%ther mechanical defects

%i&ration "isalignment

&ent shaft

Clogged$ eroded$ or other'#ise unbalanced impeller 

Lac! of rigidity in the foundation

Insufficient venting (ositive suction head)

Insufficient suction pressure may also cause vibration$ as #ell as noisy operation

and fluctuating discharge pressure