Low-NPSHr to prevent cavitation
31 oktober 2017
Cavitation is caused by too low suction pressure, in relation to the internal resistance of the liquid in the pump and the vapor pressure of a liquid (the higher the temperature, the higher the vapor pressure). In case of cavitation, pump problems occur because of imploding 'bubbles' generating an intense shock wave. Life expectancy of the pump decreases because of deteriorating of the metal and extra wear on moving parts due to imbalance and decreased cooling and lubricating properties of the cavitating liquid. Without cavitation you are assured of a quiet and long-lasting smooth operating pump.
DP has developed a specially designed low NPSHr impeller and bottom stage casing for the DPV & DPH(S)Ipump range with significant lower NPSHr value. Due to this special low NPHSr design, the pump can be used in a wider range of applications to ensure high reliability and smooth operation of the pump even in case of low suction pressure and/or high temperature and vapor pressure of the liquid.
| Extended CFD calculation models have resulted in a design with lower fluid velocities at the core of the impeller (shown in blue). | A pump with low NPHSr impeller has the same height as the standard version and the first stage of the hydraulic package can easily be exchanged by a low NPSHr variant. |
The low NPSHr option is available for DPV(C/S) and DPH(S)I 2, 4 ,6 , 10 and 15 models in both 50 and 60 Hz.
