Strategies for Improving Life & Performance of Aging Equipment

Many of our aging facilities are still using the pumps that were purchased and commissioned during plant construction. Despite the age of this equipment, effective maintenance strategies and upgrade opportunities can extend useful life for decades more. Older pumps are often more robust than current designs, which take advantage of new manufacturing technologies to reduce the raw materials needed for construction. However, vintage equipment has its downfalls as well. It is important to understand the challenges we face when operating and maintaining vintage equipment so that we can stay ahead of potential sources for decreased reliability.

These challenges were at the forefront of an improvement project undertaken by a Canadian pulp mill. Most pulp and paper mills in North America have been in operation for decades, and many are still running with the original equipment. This facility had several BB2-style makeup liquor pumps (MULP) that were experiencing a low mean-time-between-failures (MTBF). To increase pump life and reduce the risk of unexpected downtime, the pulp mill approached Hydro’s Scotford service center for support in identifying the root causes of degradation. Hydro Scotford combined a thorough inspection process with experience in upgraded designs and materials to bring the MULP system reliability back to an acceptable level and improve overall performance. The major focus points of this project – standardization, material upgrades, and improved tolerances – can be applied to aging installations in all industries.

Read the full story in our recent case study published in World Pumps magazine.

Byron Jackson Process Water Pump Improvements

Application: Pond Process Water
Pump Details: Byron Jackson 32KXL
Pump Type: Multi-Stage Vertical

Industrial pumps are sometimes repaired or modified by smaller local repair shops that do not have the engineering oversight to ensure that the repairs and modifications meet the original design’s intent. When Hydro received this pump, it was clear that prior modifications that had been performed without engineering review were causing problems.

This pump had been “upgraded” by replacing the upper bearing with an enclosure tube, which was not part of the original design. The lack of that bearing contributed to the instability of the top shaft and may have lead to the pump’s failure.

After fully reverse engineering the pump, Hydro redesigned the existing enclosure tube to incorporate the missing upper bearing. The modification involved machining the enclosure tube into two pieces and joining them together with a coupling and adding a bushing to stabilize the shaft.

Because the spare parts provided were of an older design and no longer fit the pump, Hydro manufactured several parts. These included a new transition piece, diffusers, a new bearing, and suction bell. Moreover, the impeller vane tips were weld-repaired and re-machined, and the impellers were then balanced to 4 W/N. The pump, which was rebuilt to standard specifications and reconstructed using a durable stainless steel, was returned to service successfully.

Learn more about Hydro’s targeted upgrades for the pulp and paper industry here.

Lear more about Hydro’s Scotford service center, the service center that spearheaded this project, here.

Capability Spotlight: Adopt a Higher Standard

Improving performance and life isn’t always about making big changes to design and operation. Small improvements to the standards and processes that are used during refurbishment and assembly can result in outsized benefits.

Hydro specifies machining and fit-up tolerances that often exceed the required industry standards and are best-in-class for the pump industry. Taking the extra time to meet more stringent tolerances ensures better concentricity and parallelism of critical components, reducing the risk of contact between the rotating and stationary elements during operation. Reducing component contact will result in reduced vibration and reduce the rate of wear for close clearance components. Maintaining design clearances greatly contributes to longer mean-time-between-repairs by providing greater stiffness and damping to the rotating assembly and reducing internal recirculation, which in turn affects performance and efficiency. To learn more about the importance of maintaining design clearances, read our Hydro Learning Hub white paper on the subject.

Another improvement that is standard at Hydro for repairs of multistage barrel (BB5) pumps is a dimensional analysis to identify relative centerlines of all impellers to their respective diffusers. This process and the resulting actions to ensure centerline compatibility at each stage are essential in prolonging equipment life and counteracting latent failure mechanisms.

By adhering to stricter tolerances, requiring robust process documentation, and never cutting corners, Hydro’s rebuild process results in greater reliability and increased mean-time-between-repairs. This level of quality ensures a safer work environment for our end user customers, reduces waste by decreasing the frequency of maintenance cycles, and lowers overall cost of ownership.

Learn more about the importance of axial centerline compatibility in multi-stage pumps in this case study.

Find your local Hydro Service Center and ensure high quality equipment rebuilds.