Resolving Thermal Oil Pumping Problems with Correctly Specified Gear Pumps

A long-standing chemical manufacturing customer approached CDR Pumps after experiencing problems with two magnetically driven gear pumps used to circulate thermal oil through a large mechanical seal to prevent overheating.

Although CDR had not supplied the original pumps, we were asked to investigate the recurring problem and recommend a suitable solution.

Identifying the Cause of the Gear Pump Failure

A Root Cause Analysis identified the viscosity of the thermal oil, which was manufactured on site, as a key factor.

The high-viscosity fluid was creating excessive load on the magnetic drive, causing it to slip and preventing it from successfully re-engaging. With a mechanical seal of this size, frequent replacement was both costly and highly disruptive to the process.

Importantly, the problem was not the use of gear pump technology itself. Gear pumps are positive displacement pumps commonly used for hydraulic fluid applications and can also be suitable for handling viscous fluids such as oils.

In this case, the issue was the size and capability of the original pumps, which were not appropriate for the demands of this particular application.

Correctly Specifying the Gear Pumps

Working closely with the customer, the pumping requirements were reassessed and high-pressure gear pumps with the appropriate capacity for the application were installed.

The improvement was immediate. Mechanical seal life increased, leaks were reduced and process downtime decreased significantly.

Following the successful installation, the customer began replacing pumps across other identical applications on site to achieve the same improvements in reliability and efficiency.

Adapting the Solution for a Higher-Pressure Application

Following the success of the initial upgrade, the same customer approached CDR with a similar problem on another application. However, this time the system pressure was significantly higher and outside the operating range of the existing pump.

Working with the customer, our engineering team modified a pump from the same range to reliably handle the higher system pressure, using common spare parts.

This project demonstrates the importance of specifying a pump for the actual fluid properties and operating conditions, rather than simply selecting the correct pump technology.

If you’re experiencing reliability problems with an existing pump, our engineers can assess the application and help identify a suitable solution.

Contact the CDR Pumps team on 01933 674777 or sales@cdrpumps.co.uk