15
7. Limit of the pump pressure resistance
Avoid going over the discharge pressure of the pump as the following the limit. (at 25 degrees)
Model
20**GV1
250*GV*
400*GV3
500*GV3
250*GVF*
400*GVF3
500*GVF3
Limit (MPa)
0.25
0.32
0.41
0.53
0.32
0.41
0.45
8. Easy foamy liquid
Easy foamy liquid by stirring for surfactant reduces self-priming ability dramatically. No self-priming
sometimes happens. In this case, take measures such as placing foot valves.
9. Frequent on / off switching
Frequent switching on / off of a pump may hasten pump damage. Turn on the pump less than six
times in an hour.
10. Minimum flow rate
Operate pumps at the capacity higher than the following figure.
Model
Minimum flow rate
20Y6GV1, 2A6GV1
5 L/min (1.32gal)
2500GV1, 2501GV(F)3, 4001GV(F)3
10 L/min (2.6gal)
2502GV (F)3, 4002GV(F)3, 4003GV(F)3, 5002GV(F)3, 5005GV(F)3
20 L/min (5.28gal)
Maintenance / Consumable parts
YD-20Y6GV1 / 20A6GV1
1. Daily check
(1) Check that there are no vibrations or any abnormal noises and it works smoothly.
(2) Compare the current value during operation with the rated current value and check that the
operating load is normal. Also, the discharge pressure, capacity and current value is on the level
than ever before.
(3) Check the liquid level in the suction tank. (The empty tank during operation = the pump
damaged)
2. Periodical check
(1) Periodically overhaul is recommended for a smooth operation.
(2) When replace or carrying pumps for repair, drain and wash the pump thoroughly.
3. Consumable parts check
Periodically check the following consumable parts, and replace them if necessary.
(1) Mouth ring (No. 1-3)
Check the wear volume as viewed from the front.
Replace it if it has dents.
(2) Bearing (No. 1-2)
Check no crack / damage and rattle with the shaft.
(3) Rear thrust ring (No.2-3)/Shaft (No. 2-2)/Liner ring (No.3-6)
If they have crack, damage or abrasion, replace it.
(4) Impeller (No.1-1)
If there is abrasion or corrosion on the surface, replace it.
(5) Rear casing (No. 2-1)
If there is abrasion or corrosion inside, replace it.
Bearing
Impeller
Mouth ring
