10-1
10. Special models
10.1 Lifting
models
This section describes the lifting models.
The lifting models allow lifting operation of up to 4 m in the actual
head and of up to 6 m in the total head.
The lifting models come standard with a constant relief kit (an
orifice, a ball valve, a nipple, and a union). Connect a constant
relief pipe to the kit to send water back to the source of water
supply.
Note
For the installation procedure of the constant relief pipe, there may be an
applicable guideline or guidance from local governments or other official
institutions. Carefully check for such guidelines and follow the instructions.
Note
A standard model can be modified to the lifting model.
For further information, contact us.
[Instructions only applicable to lifting models]
(1) Ensure to install the constant relief pipe
c
for each pump.
(2) Submerge the end of the constant relief
pipe deep enough to prevent exposure to
air even if refilling of water creates waves
on the surface. In addition, keep a
distance from the suction pipe so that air
from the constant relief pipe does not enter
the suction pipe.
(3) Fully open the valve
d
during operation.
(Water flows at a rate of about 10 L/min.)
(4) Ensure to install the suction pipe
e
for
each pump, and provide a rising slope (at
least 1/100 degrees) leading up to each
pump to prevent the formation of air
pockets inside the pipe. Furthermore,
install joints in a way that no air enters
from there.
Pay special attention to determining the
pipe diameter of an automatic alternate
parallel operation type because the flow
rate of the subsequently activated pump exceeds half the maximum flow rate of water to be used.
(5) Ensure to attach a foot valve
f
with a strainer to the end of the suction pipe
e
to block entrance of
foreign matter or objects. The suction port must be located at a position more than twice as deep as the
size of the suction pipe diameter (D) below the lowest water level, and at a distance of at least 1 to 1.5
times the pipe diameter (D) away from the bottom and the side of the water tank.
(6) Do not attach a sluice valve to the suction pipe
e
.
(7) Install strong piping supports
g
to prevent the weight of the piping components from being applied to the
unit.
Fig. 10-1(a) Constant relief kit
Orifice
Nipple
Suction flange
Union
Min. 1 to 1.5D
Keep a distance from
the suction pipe.
Minimum water level
M
in. 2D
M
in. 1 t
o
1.
5D
Fig. 10-1(b) Example of piping work
