Pump Performance Tests – Flow Tests

Very often pump manufacturers, suppliers and pump end users are faced with an issue in regards to whether or not the pump specifications meet the desired output necessary, if the system designed by the consultant is practical or ensures the mechanical integrity of the pumps they have purchased and are using. Our non-intrusive flow meters can play a useful role along with other general instruments to help the customer get the data they need to make decisions.

A test might be necessary to verify the pump’s performance under certain conditions. If for example the pump is centrifugal and has been working well for many years but more recently a decline in pump output (flow rate) is noticeable, then maybe it is time to perform maintenance checks and even replace impellers. One way to start testing before anything mechanical is modified or changed is to verify what the actual pump output is currently. To achieve this, a clamp on flow meter might be an option -but all parties involved need to be confident enough that the flow meter data they are reading is close enough to the actual situation.

When a pump is delivered for the first time, the user expects it to follow a typical performance curve, and this curve is often taken using multiple points. The Pump RPM can be used as a crude method of ascertaining the current flow rate but it is not fool-proof, since it is assuming the output is always directly correlating to the RPM. To remove doubts related to the head efficiency, horespower and NPSH, a full performance characteristic of the pumps might have to be calculated.  A non-invasive flow meter that people trust will help shed some light on what the flow rates are.

Everything in a pumping system will affect something else. A test to ensure the current integrity of a pump means that we are trying to verify that the pump is running without any serious mechanical issues. Pumps that are working optimally will have a healthy bearing temperature, vibration level and no visible leaks coming from soft parts like seals, gaskets and o-rings. A suitable flow meter can be attached to the outside of the pipe for a decent amount of time and flow rates verified while the technician is checking the temperature changes on rotating parts like bearings.


Checking pump suction ability and cavitation, running the pump at desired operating speeds (using a VFD) are a lot easier with a non-intrusive flow meter. The traditional methods are supplemented by a trustworthy tool that is going to give an accurate and repeatable flow reading at both low and high flow. Our customers have reported that our Transit-time cross-correlation flow meters do indeed make life much easier.


Piping issues

There are certain other things that can be checked using our flow meters. Its not always the pump’s fault. The issues could be piping too. In some cases, we have the wrong type of pump and so on! The flow meter has often helped technicians save time by reading flow velocities at different piping sections and flow data for each point is collected and analyzed to find out where the piping went wrong.


Liquid Types not an issue

One of the advantages with our tools is that the user might need to use it on pumps that are pumping oil or chemicals and is looking for a device that is not only Reynold’s compensated for water but for liquids with different densities and kinematic viscosities.