The conditions for turning the pump are determined by the pump itself and the inhalation device. Therefore, the conditions for studying the occurrence of auto erosion should be considered from both the pump itself and the inhaling device. The basic relationship of pumping auto erosion is

NPSHC≤NPSHR ≤ [nPSH] ≤NPSHA

NPSHA = NPSHR (NPSHC) -The pump starts in auto erosion

NPSHA NPSHA> NPSHR (NPSHC) -The pump non -etching

NPSHA in the formula —— The amount of steam erosion in the device is also called an effective volume of the volume.

NPSHR —— Pump erosion balance, also known as the essential steam erosion waste or pump inlet dynamic pressure drop. The smaller the more anti -steam erosion performance, the better;

NPSHC -critical steam erosion balance refers to the amount of steam erosion balance that decreases a certain value of the corresponding pump performance;

[NPSH] —— The amount of steam erosion in the Xu is to determine the amount of steam erosion used for the use of pumps. Generally, [npsh] = (1.1 ～ 1.5) NPSHC.