shear pump’s common failures and shooting list

1. Exceeding shaft power

Reason

a. The impeller fractionates the end face of pump
casing .The sleeve or auxiliary impeller.

b. The pump works under the condition of than the
designed head .

c. The packing is over -tightened .

d. The belts slips .

Method of shooting

a. Adjust the clearances

b. Inspect the complete machine and properly close the
delivery valve for the pump to operate at the design point .

c. Readjust the locking force of gland .

d. Re-tighten them (check the two pulleys installation
position ).

 

2. Fall in head and capacity

a. Big particle jams the suction pipe and flowing
channel of impeller .

b. Fall in speed

c. The impeller is worn .

d. Too much clearance between the impeller and end face
of pump casing and the increased leakage .

e. The opening degree of inlet valve is little .

 

Method of shooting

a. Clear away the jamming object

b. Operate the pump at the rated speed .

c. Renew the impeller

d. Adjust the impeller .

e. Increase it .

 

3. The bearing is overhead

 

a. The lubricant is too much or little .

b. There is impurity in the lubricant .

c. The bearing is worn .

 

Method of shooting

a. Keep the surface oil at the limited lever of the
dipstick .

b. Change of the lubricating grease .

c. Renew the bearing .

 

4. The pump produces vibration and unusual noise

a. The impeller is worn and non-equilibrium

b. The bearing is worn

c. The connection is loose

d. The pump occurs cavitation

 

Method of shooting

a. Renew it .

b. Replace

c. Tighten the loosened locations .

d. Improve the suction condition to prevent air from
getting into the pump .

 

5. The leakage is excessive when stopping the pump

a. The seal is over-worn

b. The shaft sleeve is extremely worn .

c. The packing is extremely worn .

d. The debris gets into the packing rings .

6. All the splits of packing rings are in the same
direction .

Method of shooting

a. Renew

b. Replace the sleeve

c. Renew

d. Re-install

e. Clear away the debris and clean the seals .

f. Re-fill them as request .