Select Page

Centrifugal Pumps

From food and beverage to pulp and paper, refining and petrochem to municipal water and wastewater, centrifugal pumps are the workhorse of industry whenever water or other fluids need to be transferred. While most centrifugal pumps hold less oil than most gearboxes or hydraulic systems, they are often no less critical to plant success. Like most equipment, ensuring that the oil is healthy and at the correct level, as well as excluding contamination is key to pump reliability.

Talk to an Expert

Contact Us

Since pumps are most frequently used to transfer water and other aqueous chemicals, water ingression through shaft seals is a leading cause of contamination. For this reason, most newer pumps are equipped with IP-67 rated labyrinth-style bearing isolators versus traditional packing. However, even with a bearing isolator, water in the form of humid air can still migrate through the seals into the pump, causing significant reduction in bearing life

Installing a desiccant breather in place of the fill plug not only helps to reduce headspace humidity inside the pump bearing housing, in turn lowering the water content in the oil, it can also serve as an indicator of seal leakage by observing the pink-to-blue color change of the breather.

Essential modifications for centrifugal pumps include:

• Desiccant breather to control particle and moisture ingression and reduce headspace humidity
• 3-D BullsEye® to check level
• Oil Sight Glass (OSG) installed on the drain to check for free water, sediment and oil discoloration
• Quick connects on the drain and fill ports for easy oil changes, top-offs and oine filtration

Small centrifugal pumps have bearings with an outside diameter of 4” (100 mm) or less. That means the ball in the radial support and thrust bearings can be as small as ½” (12.5 mm). Since the correct oil level is halfway up the lowest rolling element, that means the oil level needs to be maintained within a tolerance of ±1/8” (1-2 mm).

Because of this, many pumps are equipped with constant level oilers (CLOs) to maintain levels. However, even with a CLO, being able to visually check levels is an important daily or weekly maintenance check.

The costs associated with water and particle ingression in pumps are multifaceted, impacting immediate repair needs and long-term operational efficiency. A single pump failure due to this type of contamination can often range from $5,000 for minor issues in non-critical applications to over $100,000 in severe cases involving major downtime, environmental impacts or product losses. Preventive measures such as regular maintenance, proper filtration, and the use of high-quality breathers can mitigate these costs by ensuring the pump and the overall system remain in optimal working condition.

Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.

Pump Reliability Whitepaper

Pumps can often been the largest single asset class in a facility, and having these them up and running properly is critical. For this reason, most plants pay particularly close attention to pump reliability and often track Mean Time Between Failure (MTBF). In many plants, pump MTBF varies between 5-8 years depending on the maturity of maintenance practices. However, with just a little effort, significant improvements to pump reliability and longevity can be achieved through the application of precision lubrication practices.

Modify Your Equipment to Seal and Protect It

Receive a downloadable plan for your specific make and model of equipment. Modification plans include simple addition of hardware such as quick connects, level gauges, breathers and sample ports to facilitate lubrication best practices.

Additional Resources