NPSHvärden

NPSHvärden, also known as Net Positive Suction Head, is a critical parameter in the design and operation of centrifugal pumps. It represents the difference between the absolute pressure at the pump suction and the vapor pressure of the fluid at the suction temperature, minus the velocity head at the suction. NPSH is essential for ensuring that the pump operates efficiently and avoids cavitation, a phenomenon where vapor bubbles form in the liquid, leading to reduced pump performance and potential damage.

The NPSH required (NPSHr) is a characteristic of the pump and fluid being used, and it is provided by the pump manufacturer. The NPSH available (NPSHa) is a function of the system design and operating conditions, including the suction lift, suction piping design, and fluid properties. To prevent cavitation, NPSHa must be greater than NPSHr.

NPSH is typically measured in meters or feet of the pumped liquid. It is influenced by factors such as suction lift, suction piping friction losses, and fluid temperature. Proper calculation and management of NPSH are crucial for the reliable and efficient operation of centrifugal pumps in various applications, including water supply, industrial processes, and HVAC systems.