Product Manual
Specications Information and Repair Parts Manual
DIAPHRAGM PUMPS
3370-PRV-OE 5 7/2020
Diaphragm Pumps
Symptom Possible Cause(s) Corrective Action
Pump will not prime or retain 1. Air leak in suction line 1. Repair or replace
prime after operating 2. Defective apper valves 2. Replace
3. Clogged foot valve or strainer 3. Clean or replace
4. No liquid in suction line 4. Fill suction line & pump with liquid
5. Material jammed in pump well 5. Clean (See Maintenance)
Flow rate is slow 1. Incorrect driver speed 1. Increase speed (see Specications)
2. Piping is fouled or damaged 2. Clean or replace
3. Clogged pump 3. Clean
4. Discharge line restricted or undersized 4. Flush out piping or replace
5. Collapsible discharge hose 5. Replace with rigid or non-collapsible
hose
6. Too many bends 6. Straighten hose
7. Lines are too long 7. Shorten lines
Pump runs but no uid 1. Faulty suction piping 1. Replace
2. Pump located too far from uid source 2. Place pump closer to source
3. Gate valve closed 3. Open gate valve
4. Clogged strainer 4. Clean or replace
5. Discharge height too great 5. Lower discharge height
Pump starts and stops pumping 1. Leak in suction line 1. Repair
2. Leak in foot valve 2. Repair or replace
3. Diaphragm has a crack or hole 3. Replace
4. Defective or clogged apper valves 4. Clean or replace
Excessive noise while pump in operation 1. Pump not secured to rm foundation 1. Secure properly
2. Restricted suction line 2. Clean or correct
Pump stalls repeatedly or 1. Discharge height over 25 feet of head 1. Lower height (see Specications)
stops for no apparent reason 2. Material jammed in pump well 2. Clean out pump well (See Operation &
Maintenance section)