What is the minimum pressure required at a pump's inlet to prevent cavitation called?

The minimum pressure required at a pump's inlet to prevent cavitation is known as net positive suction head (NPSH). NPSH is a critical parameter that indicates the amount of pressure available to keep the liquid in the pump from vaporizing. When the pressure at the pump suction falls below the vapor pressure of the liquid, vapor bubbles can form, leading to cavitation, which can cause significant damage to the pump impeller and other components over time.

Net positive suction head is calculated by taking the total pressure at the pump inlet, adjusting for the vapor pressure of the liquid being pumped, and considering factors like height differences in the system. A sufficient NPSH value ensures that the pump operates efficiently and reliably without the risk of cavitation, which can lead to performance issues and costly repairs.

Dynamic pressure, static pressure, and flow pressure refer to different aspects of fluid dynamics and pressure measurement, but they do not specifically address the condition of preventing cavitation in pump operation like NPSH does. Understanding NPSH is crucial for ensuring the successful design and operation of pumping systems in refrigeration and air conditioning applications.