Circulating Pump

Operating conditions

The product is suitable for conveying liquids that are thin, clean, non-corrosive, non-flammable and explosive, and do not contain solid particles, fibers, or physical and chemical properties similar to water. When used in situations where the liquid is viscous or dense, it will cause a decrease in the pump characteristic curve and an increase in energy consumption.

• Maximum working pressure: conventional type is 12 bar; special type is 16 bar
• Liquid temperature: -15℃ to 110℃
• Ambient temperature: up to + 40℃
• Elevation: up to 1000m
• Rotation direction: clockwise (look down at the motor blade end)
  
  

Minimum inlet pressure - NPSH

If the pressure in the pump is lower than the vaporization pressure of the liquid being transported, cavitation may occur. To avoid cavitation, ensure that there is a minimum pressure and a maximum suction range H (m) on the pump inlet side, which can be measured as follows:

• H=pbx10.2-NPSH-Hf-Hv-Hs
• H-Maximum suction (m)
• Pb - atmospheric pressure (bar)
• In a closed pipeline, it can be considered as the system pressure (bar) of a closed system.
• NPSH-net positive suction head (meters)
• It can be read at the maximum flow rate corresponding to the NPSH curve in the performance curve.
• Hf - Pipe loss at inlet (meters)
• It is the value corresponding to the maximum flow rate that the pipeline may generate.
• Vaporization pressure of Hv-liquid (meters)
• The magnitude of its value depends on the vaporization pressure value of the liquid temperature
• Hs - safety margin (meters)

The minimum pressure head is 0.5 meters.

By calculation, if "H" is positive, it means that the pump can operate at the maximum suction stroke "H"; if "H" is negative, it means that the pump must have a pressure head with a minimum pressure of the corresponding "H" meter at the inlet can run normally.

Note: Generally, the above calculation is not performed. "H" should only be calculated when using a pump in the following situations:

• The liquid temperature is high
• The liquid flow rate exceeds the rated value
• Large suction stroke or long inlet pipeline
• The system pressure is too small
• Poor import conditions