CPspec

CPspec guides to determine the three key factors of a centrifugal pump design specification such as ‘System Head’, ‘NPSHA’ and ‘Sizing’ in order to unveil the potential for energy savings. Selecting a right spec for the given application is often iterative process and is very essential for its energy efficiency and long-term satisfactory performance. This app can guide through that process by quickly modifying the generic pump data to fit an individual application. Further one can save all data in a file and reload the spec sheets for monitoring and review. Hence this app can be very helpful to all practicing engineers and designers to accomplish this goal.

By default, pump manufacturers provide performance curve for water that is valid for other liquids too. However, there could be significant impact on performance due to increase or decrease in system head as well as NPSHA while using other liquids or oils at elevated temperatures. One can quickly compute these values for liquids other than water using the model provided in this app. There are four main sections in this app and its features are briefly given below with respective screen shots.

Fluid Properties:
Water used as a standard liquid medium and its thermo physical transport properties are determined based on IFC 1967 for the given temperature. For liquids other than water, users can use custom liquid by providing its properties for computation of system head and NPSH. Users can choose any unit standard (SI or USCS) to input the data.

System Head:
One can quickly compute for a given pipe size, valves and fittings. If the delivery system uses different diameter pipes, users can input the total equivalent length of a given diameter pipe for computation purpose. Based on property data, the app computes the total pressure drop and dynamic head. Total head is then computed based on the static head data (pump center line to final delivery) and final value is posted to the spec sheet.

NPSHA (Net Positive Suction Head Available):
This is an important design parameter in order to avoid any cavitations in the pump. Every pump manufacturer provides their data on NPSH requirement. Therefore, it is very essential to compute this value to ensure that pump meets this requirement. Based on the property and size data, this is computed for a default suction line that can be edited for accuracy.

Pump spec summary:
Summary sheet provides all the major key pump design parameters with general guidelines to help the users to choose the right pump for their application. This is to further ensure energy efficiency and long-term performance of the pump.