TM 5-4320-200-13&P
4-4. CENTRIFUGAL PUMP.
The centrifugal pump is coupled to the gasoline engine or electric motor. The pump case
houses the impeller, wear plate, and seal and serves as a water chamber with suction and discharge
ports. The volute, which bolts to the front of the pump case, completely encirles the impeller. A check
valve prevents water backflow through the pump.
4-4.1. Troubleshooting.
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Table 4-2 is used for organizational maintenance activity troubleshooting. This table is to be
used in conduction with the preventive maintenance table contained in paragraph 2-2.
Table 4-2. Maintenance Activity Troubleshooting.
M A L F U N C T I ON
TEST OR INSPECTION
CORRECTIVE ACTION
1.
PUMP FAILS TO PUMP TO RATED CAPACITY.
Step 1- Check if check valve is defective.
Replace check valve. (Refer to para 4-4.3)
Step 2- Check if impeller is clogged or broken.
Flush pump case or replace impeller. (Refer to para 4-4.2)
Step 3- Check pump case for leaks, cracks, or damage.
Repair or replace case. (Refer to para 4-4.2)
Step 4- Check if packing seals are worn or defective.
Replace packing seals. (Refer to para 4-4.2)
Step 5- Check if clearance between wear plate and impeller is excessive,
Install shims as required. (Refer to para 4-4.2)
2. PUMP FAILS TO PRIME.
Step 1- Check if check valve is defective
Replace check valve. (Refer to para 4-4.3)
Step 2- Check if suction flange is loose or defective,
Tighten mounting nuts or replace suction flange. (Refer to para 4-4.3)
Step 3- Check if packing seals are worn or defective.
Replace impeller. (Refer to para 4-4.2)
4-12
Change 5
