8
PRECAUTIONS IN HANDLING THE SELFREE
Remove the blind seals on the outlet and inlet of the pump before attaching pipes to
them.
Do not rotate the motor in the reverse direction. (Except for an instantaneous reverse
rotation to check the rotational direction.)
The pump has a patented structure to retain a certain amount of liquid in the casing
when the pump is stopped.
If liquid that foams easily is primed, it may take much time or make it impossible to
pump liquid, causing problems by generating heat.
If there is excess slurry, it will collect behind the impeller. This will mar the sealing
ability, causing the liquid leakage.
A liquid with a high specific gravity or a high temperature will take more time to prime.
In such cases, it is necessary to take some appropriate measures such as shortening
the length of the suction pipe.
Pumping the liquid with too much air will mar the self-priming ability. If the pump is
operated for extended hours in this condition, the liquid temperature will rise, causing
the pump and casing to be distorted and/or damaged by heat.
To prevent the self-priming capacity from lowering, it is necessary to have a vertical
pipe longer than 3.3 ft. (1 m) attached to the outlet, with a bypass pipe for air exhaust.
At the same time, it is also necessary to keep the pipe length as short as possible on
the suction side to minimize pipe resistance loss.
The height of suction may be decreased depending on the type of liquid used, the
liquid’s specific gravity, and the liquid’s temperature It is recommended to set the
height of suction at a relatively low level to allow for the possible decrease.
To prevent the pump from being distorted by thermal expansion and thereby also
prevent any liquid from leaking, it is imperative that the user equip the piping with
bends and expansions.
When using the pump to transfer waste liquid, it is imperative that the user equip the
suction hole with a strainer to prevent dust and other foreign matter from entering the
pump.
When moving the pump ( for transport or repair), it is necessary for the user to drain
the liquid and wash the pump with water completely to ensure safety.
Handle the pump carefully without any hard impact as its base is constructed of resin.
