Tandem Operation (LH / LH-W)




High-Head Dewatering Pumps

Discharge Bore(mm) 50 - 100
Motor Output(kW) 3 - 30

"Tandem operation" is an operation method that connects two pumps of the same model in series. This provides double pump head at the same flow rate in comparison with that of a single pump. The principle of tandem operation is the same as that with multistage pumps. The LH and LH-W series pumps adopt the center flange construction to align the discharge pipe with the cylindrical pump center axis.* Connecting the pumps in series with the tandem connector can provide higher pump head without affecting the advantage of the slim design. At construction sites, there are many cases where a higher pump head is required as construction work progresses.
In such cases, the addition of a tandem pump may meet the required pump head, instead of using a new pump.
* Available as an option for separately purchased LH33.0 and LH23.0W.

Performance Curves

The intermediate connection pipe is not required in the range indicated as a bold line on curves.
If the required total head exceeds the maximum head of the pump without an intermediate connection pipe (indicated as dashed line), an intermediate connection pipe of a length corresponding to the excess amount or more is required.

Model Selection
Max. Head
in Tandem
Max. Head
w/o Intermediate
Connection Pipe
80 LH33.0 3 Three D.O.L. 36 / 44 33
50 LH23.0W 3 Three D.O.L. 78 / 86 50
50 LH25.5W 5.5 Three D.O.L. 130 97.5
80 LH311W 11 Three D.O.L. 162 121.5
80 LH322W 22 Three D.O.L. 204 / 216 162
100 LH430W 30 Three Star-Delta 246 / 254 190.5