Your centrifugal pumps are essential to your production but determining when they need attention can be difficult. Keeping centrifugal pumps running efficiently requires the use of condition monitoring instead of regularly scheduled overhauls that can cause unnecessary downtime.
Pump performance depends on several factors, meaning maintenance estimates are sometimes inaccurate. Pump condition monitoring helps you to assess the degradation of parts and lubricants, and then schedule maintenance and repairs as needed.
Pump Condition Monitoring Methods
Condition monitoring of centrifugal pumps includes the head-flow method, thermodynamic method, and the shut-off head method. Employing these techniques will take the guesswork out of pump maintenance.
The head-flow method is a reliable test for predictive pump maintenance. This method depends on measuring the pressure of the head using test gauges to find the differential pressure measurements across the orifice plate. Once you establish standard measurements, you conduct regular tests to check for any significant changes in the pressure. Depending on your cost analysis, an overhaul may be needed at this point.
The thermodynamic method relies on temperature rise measurement of fluid in the centrifugal pump. Normal differential temperatures are minimal, so the measurements of these temps must be exact and done while the pump is producing a normal flow. A significant rise in differential temps indicates wear and tear are an issue.
Shut-Off Head Method
The shut-off head method is another effective way to determine when pump maintenance is needed. However, this method is not appropriate for all pumps. Those pumps that have more power at shut off than at the duty point cannot handle this test. You need to take the suction and discharge pressures when the discharge valve is closed for a brief period, approximately 30 seconds. Liquid temperatures are also needed to figure density and convert the readings into head values. The head-flow curve of the test results will trend toward the zero-flow axis if the pump is worn.
Determining When to Overhaul Your Pumps
You must interpret the results of your testing method to determine when pump maintenance is necessary for your process. Steady deterioration means you will need to do a cash flow analysis to see if the overhaul will be worth the money. When your electricity use increases enough, the overhaul will clearly be worth the investment to reduce these energy costs.
Obviously, you must weigh production losses as well. If your centrifuge is slowing down production, you won’t be able to delay the overhaul without incurring significant losses.
Contact DXP for Expert Help
When you need industrial maintenance services, the experts at DXP can help. We offer expert service and advice on sophisticated industrial equipment, including industrial pumps. We understand the importance of condition monitoring in your business and stand ready to help you determine what corrective measures your equipment needs.
Pump condition monitoring is vital to maintaining high efficiency at your company. Regularly scheduled maintenance does not help you accurately predict when maintenance or a pump rebuild is needed. Several reliable methods exist to help you with pump vibration monitoring and overall condition monitoring of centrifugal pumps.