Blog

TROUBLE SHOOTING GUIDE:
NDP-20/25/32/40/50/500/80

This is a troubelshooting guide for the following Yamada AODD Pump series;
NDP-20 series, NDP-25 series, NDP-32 series
NDP-40 series, NDP-50/500 series, NDP-80 series

　INDEX
▼ 1. Pump does not run.
▼ 2. Pump runs, but fluid does not come out.
▼ 3. Flow (discharge volume) decreased.
▼ 4. Liquid leakage from exhaust port (silencer) .
▼ 5. High air consumption during operation.
▼ 6. Irregular noise. 　
▼ 7. Irregular vibration.
▼ 8. If you still can't solve the problem...

1. Pump does not run

Cause	Action to be taken
The exhaust port (silencer) of pump is clogged with sludge.	Check and clean the exhaust port and silencer.
Air is not supplied.	Start the compressor, and open the air valve and air regulator.
The supply air pressure is low.	Check the compressor and the configuration of air piping.
Air leaks from connection parts.	Check the connection parts and tightness of bolts.
Air piping or peripheral equipment is clogged with sludge.	Check and clean the air piping.
The flow valve on the discharge side is not open.	Open the flow valve on the discharge side.
The spool stopped in neutral position.	Press the RESET button.
The fluid piping is clogged with sludge.	Check and clean the fluid piping.
The pump is clogged with sludge.	Disassemble the casing, check and clean.

・Refer to the maintenance manual and follow the instructions to diasseble your pump.
▶ Maintenance Manual for NDP-20/25/32 series
▶ Maintenance Manual for NDP-40/50/500/80 series

・If any of the above mentioned causes does not apply to your problem, contact your dealer or our regional office.
▶ Contact Us

▲ Back to Top

2. Pump runs, but fluid does not come out.

Cause	Action to be taken
The suction lift or discharge head is long.	Confirm the piping configuration and shorten the length.
The discharge-side fluid piping (including the strainer) is clogged with sludge.	Check and clean the fluid piping.
The valve on the suction side is not open.	Open the valve on the suction side.
The pump is clogged with sludge.	Disassemble the casing, check and clean.
The ball and valve seat are worn out or damaged.	Disassemble the manifold, check and replace parts.

3. Flow (discharge volume) decreased.

Cause	Action to be taken
The supply air pressure is low.	Check the compressor and configuration of air piping.
Air piping or peripheral equipment is clogged with sludge.	Check and clean the air piping.
The discharge-side flow valve opens differently.	Adjust the discharge-side flow valve.
Air is taken in together with fluid.	Replenish fluid and check the configuration of the suction-side piping.
Cavitation occurs.	Adjust the supply air pressure and discharge pressure, and shorten the suction lift.
Chattering occurs.	Adjust the supply air pressure and discharge pressure. Reduce inlet flow valve to adjusting liquid pressure and volume.
Icing on air-switching portion.	Eliminate ice from air-switching valve and check and clean the air filter. Use external exhaust hose to control exhaust air speed. ▶ Refer to Fig.3.2 on page 18 in the instruction manual. (click here to check details.)
The fluid piping (including the strainer) is clogged with sludge.	Check and clean the fluid piping and strainer.
The exhaust port (silencer) of the pump is clogged with sludge.	Check and clean the exhaust port and silencer.
The pump is clogged with sludge.	Disassemble the casing, check and clean.

4. Liquid leakage from exhaust port (silencer) .

Cause	Action to be taken
The diaphragm is damaged.	Disassemble and check the pump and replace the diaphragm.
The fastening nuts for the center disk are loose.	Disassemble and check the pump. Tighten the nuts.

5. High air consumption during operation.

Cause	Action to be taken
The seal ring and sleeve are worn out.	Disassemble the air-switch portion, check and clean. Replace parts as necessary.

6. Irregular noise

Cause	Action to be taken
The supply air pressure too high.	Adjust the supply air pressure.
The spool oscillates and occur ball chattering.	Adjust the supply air pressure and discharge pressure. Reduce inlet flow valve to adjusting liquid pressure and volume.
The pump is clogged with sludge with particles of larger than the permissible diameter.	Disassemble the casing, check and clean.

7. Irregular vibration

Cause	Action to be taken
The supply air pressure is too high.	Adjust the supply air pressure.
The spool oscillates and occur ball chattering.	Adjust the supply air pressure and exhaust pressure.
Connection parts and pump mounting are loose.	Check each connection part and tighten the bolts.

8. If you still can't solve the problem...

If you still can't solve the proble, please contact your delaer or our regional office.
Please provide the following information;

Pump model (e.g., NDP-20BAT), Serial No. (shown on the product label attached to your pump.)
Operating condition（fluid, flow rate, pressure）
Purchase date
Total operating time (Approx.)
Failure situation（e.g., when it occurred, what happened）

Back to case blog list

TROUBLE SHOOTING GUIDE: NDP-20/25/32/40/50/500/80

TROUBLE SHOOTING GUIDE:
NDP-20/25/32/40/50/500/80