The Hidden Costs of Cheap Repairs 

Why Technical Expertise plays a Critical Role in Equipment Maintenance

As the industrial world becomes more competitive, reducing costs is key for maintaining an advantage in the marketplace. As such, many end users have become more cost-conscious when approaching equipment repair. In some services- where equipment is not complex and performance doesn’t affect process availability or quality- this strategy can provide some benefit. However, the short-term gain of a lower repair price often turns into long-term cost increases when a lack of engineering capability impacts equipment reliability and performance.

The importance of engaging with a facility that has strong engineering capabilities and subject matter expertise was proven during a series of boiler feed pump repairs for a Canadian biomass power plant. Like many biomass facilities, this plant had segmental ring boiler feed pumps, also commonly referred to as BB4 pumps. This is a complex design installed in a high energy, critical application, with numerous stacked and nested components that must be kept in alignment.

In this case, a small shop had completed several repairs that had resulted in high vibration and performance issues. These pumps were a legacy design that was no longer supported by the OEM and required engineering knowledge to properly refurbish and set the balance device. As such, it was important to find a repair partner that had a strong understanding of pump design. The plant worked with Hydro’s Scotford facility to bring these “bad actor” pumps back to optimal performance.

Read the full case study in World Pumps‘ March/April 2025 edition here.

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.

Modifying Existing Equipment to Maintain Operational Standards

Many aging manufacturing facilities have witnessed changes in market demand that have altered their product slate and capacity. These changing system demands often cause equipment that was previously well-sized for the application to run significantly away from the operating range where peak efficiency and reliability are achieved. Running in this mode drives up the life cycle cost of equipment due to short maintenance cycles and wasted energy. In cases where reliability is severely compromised, equipment operating costs can also be accompanied by risk to production due to mid-cycle failures and unavailability of equipment.

To maintain safe, reliable and cost-effective operation, it is important to ensure pump systems are optimized. When approached with the need to optimize a pump system, many end users will look to purchase new equipment for the changed demand. This can be a costly and time-intensive endeavor, as new equipment installation is often accompanied by baseplate and piping modifications that require the system to be taken offline. In contrast, modifying the existing equipment to meet the new system needs provides a custom solution that maintains the original footprint, can be completed on a more aggressive timeline and often provides a more custom fit to the system.

The decision to perform one such modification was made by a major Gulf Coast oil refinery that was running at a significantly lower flow than the original system demand. The site reliability team worked with Hydro to design and implement an extreme downrating of the existing equipment. The result was an optimized system that improved reliability of not only the pump, but other affected system components. 

Read our latest case study published with Pumps & Systems magazine where Hydro’s Sergio Ramos outlines how the process for this downrate and what the final outcome was for the end user.

Learn more about Hydro’s engineering services.

Ahlstrom Makeup Liquor Pump

Application: Make-Up Liquor
Pump Details: Ahlstrom Model 2LRS-20
Pump Type: 2-Stage Overhung

When a pulp mill’s make-up liquor pump failed, it was sent to Hydro’s Scotford facility for refurbishment and upgrade to restore reliability.

Hydro’s standard disassembly and inspection process uncovered a path for abrasives to reach the wear rings. Heavy localized wear was identified at the casing, behind the casing wear ring.

 

Additionally, the pump was experiencing excessive leakage of the seal water and black liquor. The millwrights were unable to properly adjust the packing gland because the 2-bolt packing gland follower was cocked on the studs due to the high pressure of the seal water. This misalignment also caused significant wear to the diffuser vane tips.

Hydro manufactured new wear rings without slots to prevent the abrasive material from damaging the case and minimize wear behind the casing wear rings. The worn areas of the casing and a new sleeve were overlaid with tungsten carbide to prevent further damage.

Hydro designed and machined a 4-bolt split packing gland follower to help maintain alignment of the packing gland follower with the stuffing box. A special material was installed to help cool and lubricate the seal to allow the proper distribution of seal water.

The diffuser vane tips were welded to restore them to their pre-wear length and the impellers were balanced to a stringent level of 2 W/N. The 2 stage pump was built vertically to ensure centerline compatibility of stationary components.

This engineered rebuild provided improved reliability for the makeup liquor pump.

Learn more about Hydro’s focused improvements for the pulp and paper industry here. Read more about Hydro Scotford here.

Innovative Vertical Pump Sealing Solutions

Upgrade in Action: HydroSeal 

Vertical pumps have reliability and maintenance considerations unique to their design and application. One of these considerations is the pump seal design. Many vertical pumps rely on packing in lieu of mechanical seals. While it is a less sophisticated design, packing has benefits for vertical pumps, including greater ability to handle fluid with particulates, less sensitivity to misalignment, and greater stiffness and damping provided at the seal location. However, packing also has multiple disadvantages, foremost of which is the need to continuously adjust the packing gland to maintain the desired leakage rate and the requirement that some fluid must leak to the atmosphere. The cost associated with replacing worn components in the packing area is another notable drawback.

 

In cases where any of the disadvantages associated with packing or a mechanical seal noticeably impact reliability or the cost of operation, upgrading to a seal casing design is an attractive alternative. This is the decision that a pulp and paper mill in the Southeastern US made when experiencing reliability and environmental concerns in their River Water pump system. Faced with the need to install a new sealing device, they decided that the ability to avoid aboveground leakage and eliminate time-consuming periodic maintenance justified the investment in a vertical pump seal casing.

Read the full case study in World Pumps March/April 2024 edition.

Learn more about Hydro’s Hydro South service center and Hydro’s Engineering Services.