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Hitachi Industrial Products, Ltd.Pump system

This pump can handle rapid sewage inflows in urban areas.

Standby Pump

As this pump can start regardless of the water level in the suction sump, can stand by at full speed when flooding and can continuously operate until no danger of flooding.

Image: Structural of the pump
Structural of the pump


  1. The standby pump can stand by at full speed under no water in the suction sump prior to inflow of water.
  2. No frequent starting and stopping.
  3. An automatic flow rate adjustment function allows the standby pump to operate under the low water levels.

(In-house comparison)

Main applications

  • Vertical-shaft semi-axial flow pump
  • Vertical-shaft volute semi-axial flow pump

Comparison to conventional pump

Although the conventional standby pump requires bearing cooling water supplied externally, the current standby pump does not require the external water.

Image: Structural schematic of the pump
Structural schematic of the pump

Features of waterless-type standby pumps

  1. Since injection equipment for bearing cooling water is not required, reliability can be improved.
  2. Costs for the bearing cooling water injection equipment and bearing cooling water can be reduced and, maintenance and management costs can be decreased.
  3. Air pipes are installed at the top end of the discharge piping, drainage holes are installed on the top part of the impeller, and airlock countermeasures are implemented.
  4. The pump is set up in steps, and draining in phases can decrease the power supply load.

(In-house comparison)

Operation types

The operation system of the standby pump is divided into standby operation, idle running automatic flow rate adjustment operation, and discharge operation.

  • Standby by operation divided under idle running
  • Automatic flow rate adjustment operation under air suction at any water level
  • Discharge operation under air suction

Image: Operation system schematic
Operation system schematic

Main applications

  • Range of application: 400 to 2000-mm pump bores
    Pump discharge diameter, 400 to 2000mm