3-4
(20) Do not put a cover or filter over the motor. Otherwise, the temperature may increase inside the
motor, thus leading to an unexpected failure.
(21) Rotate the main shaft by hand to check smooth rotation. To rotate the shaft by hand, remove the
screws of a strainer and turn the impeller nut with a T-shaped wrench. If the rotation is stiff or not
uniform, there may be some rust or foreign matter inside the pump. Inspect the pump in such a
case.
Warning
Before rotating the pump shaft by hand to check it, be sure to turn off the
main power. An unexpected start of the pump may cause an accident.
3.4 Precautions for piping work
(1) The pipes must be as short and straight as possible with minimal joints and valves. Use pipes
whose bore size is equal to or larger than the discharge port of the pump. If the piping size is small
or there are many bends, the discharge rate may become low.
(2) Ensure to provide adequate pipe supports so that the weight of the piping system will not be
applied directly to the pump body.
Caution
Do not allow the weight of the pipes to rest on the pump.
Otherwise, the main shaft may be displaced from the center, thus leading
to equipment damage, vibration, or noise.
(3) Do not forcibly screw a pipe into the pump. Otherwise, it may break the joint.
(4) Securely connect the pipes so that the connections are kept completely airtight without leakage.
Prevent leaks of liquid and air with seal tape, liquid packing, or other means. Firmly wind the seal
tape while paying attention not to block the piping.
(5) Use a tank (oil tank) with as large a capacity as possible.
* It is recommended to use a capacity of at least three times the discharge volume per minute.
Too small a capacity may cause problems such as the rise of liquid temperature, pump damage
caused by the suction of cutting powder etc., and lower discharge rate caused by bubbles.
When you supply a pumping liquid into a tank (oil tank), gently pour it to prevent the introduction of
air.
(6) Do not allow a large amount of cutting powder, dirt, or other contaminants to get into the pump
section. Failure to observe this may clog the pump strainer, damage the pump, or significantly
deteriorate the performance. Use liquids that are subjected to primary treatment through a net
cage, a chip conveyor, a magnetic separator, etc.
(7) If water hammer may occur, attach a pressure damper (e.g. accumulator).
(8) If there is an upward curve on the discharge pipe, ensure that air can be vented from the section.
(9) If you provide a relief pipe on the discharge side of the pump, also provide a sluice valve in the
middle of the relief pipe to adjust the relief volume.
Note
If the amount of liquid released from the relief pipe is too much, the liquid
temperature easily rises in the tank (oil tank).
(10) On completion of the piping work, be sure to clean the tank (oil tank). Pay attention not to
contaminate the system with foreign matter.
