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[6]
If the diameters of the pump suction port and the suction pipe are different, use an eccentric reducer pipe.
Connect the eccentric reducer pipe so that the upper surface is level. In any case, never use a suction pipe with a
diameter smaller than that of the suction port.
[7]
It is also recommended, in the case of flooded suction, that a gate valve be installed on the suction pipe for
easier overhaul inspection of the pump. Keep the gate valve fully open during ordinary pump operation; it is
required to be closed only during an overhaul inspection.
[8]
When circulating a dangerous liquid, arrange the flushing pipes so that internal cleaning is possible when
disassembling the pump.
[9]
The diameter of the suction pipe must be larger than that of the pump suction port.
[10]
The end of the suction pipe should be located 500 mm or more below the surface of the liquid.
[11]
A screen should be provided at the inlet in the suction tank to prevent the entry of foreign matter into the suction
pipe. The end of the suction pipe should be 1~1.5 D (D: diameter of suction pipe) or more away from the
bottom of the suction tank. Note that the entry of foreign matter may cause the pump to malfunction.
[12]
In the case of the suction lift method, install a foot valve on the suction pipe.
Note: The items [10], [11], and [12] above are applied to the suction lift method.
M
Discharge piping
[1]
Use a support so that the weight of the pipe is not applied to the pump as load.
[2]
If a method other than flooded suction is employed, install a priming pipe.
[3]
If the pipe is too long the piping resistance may increase, hampering the pump's performance. The diameter of
the pipe should be determined by calculating the piping resistance.
[4]
A check valve should be installed if any one of the following conditions is present. When selecting the check
valve, consider the check valve pressure limit (including the influence of water hammer or back flow onto the
pump).
q
The discharge piping is very long
w
The discharge lift exceeds 15 m
e
The end of the discharge pipe is 9 m higher than the surface of the suction tank
r
Several pumps are connected parallel to one another on the same piping
