Industrial process pumps in accordance with API 610

Lifecycle Cost (LCC) Analysis is a method used to determine the total cost of ownership of a pump over its entire operational lifespan. Instead of focusing solely on the initial purchase price, LCC considers all costs associated with the pump, including installation, energy consumption, maintenance, repairs, downtime, and disposal or replacement. By evaluating these factors, businesses can make informed decisions that minimize overall expenses and improve efficiency.

For pumps, energy costs typically make up the largest portion of LCC, often exceeding the initial purchase price. Other significant factors include maintenance and repair costs, which can increase if a pump operates outside its Best Efficiency Point (BEP) or is not properly maintained. By selecting energy-efficient models, implementing predictive maintenance, and considering materials that extend pump life, businesses can reduce LCC and achieve long-term cost savings while improving reliability and performance.

Operating a pump away from its BEP—either too far to the left (low flow, high head) or too far to the right (high flow, low head)—can lead to problems such as cavitation, excessive vibration, increased energy costs, and premature wear on bearings and seals. Proper pump selection and system design aim to keep the pump as close to its BEP as possible to maximize efficiency, reduce maintenance costs, and extend pump life.

NPSHa stands for Nett Positive Suction AVAILABLE and NPSHr stands for Nett Positive Suction Head REQUIRED.

Now, what is the difference between NPSHa and NPSHr? Well, firstly NPSH is a measure of the pressure experienced by the fluid at the suction of the pump. This is always quoted in metres (or feet) rather than as a pressure because head is a fluid independent property. Keep in mind that a pump will always lift liquid to the same height regardless of the fluid's respective densities. 

NPSHa (available) is a property of the system and is calculated by the system designer giving a value of the pressure on the suction side of the pump. 

NPSHr (required) is a property of the pump. This is calculated by the manufacturer as the point where cavitation occurs. It is good practice to have a safety margin between 0.5m and 1m.