The Past, Present and Future of Pumps and Mechanical Seals (Part 1)

Pump Engineer recently had the pleasure of speaking with Scott Boyson, an expert rotating equipment consultant with over 25 years of experience in design, product development and equipment reliability programs. Scott shared his insights about the progressive nature of sealing technology and offered his perspective on the past, present and future for pumps and mechanical seals.
 
PE: Can you tell us about your professional background and how you became interested in sealing technology?

Scott: I have been involved in the pumps, seals, and pumping systems industry for over 25 years. I began my career as a design engineer developing upgrades for pumps and have worked in multiple sectors including: pump and seal design, technological innovations, training, and end-user and equipment manufacturer consulting, for industries ranging from wastewater to chemical plants and refineries.

I became interested in pursuing pump system reliability as it is a complex sector and encompasses a number of different areas. While pump and seal technologies are certainly important, there are a number of other associated areas such as pump operation, hydraulic system design, monitoring, bearing lubrication, etc., that impact reliability. Recently, I have also focused on the cost of pumping. As energy costs can be surprisingly high, I find it interesting to consider this as an opportunity for cost reduction, which can often be associated with reliability improvements too.

PE: How have you been involved with pumps and mechanical seals?

Scott: Throughout the various positions I have held, I have maintained a close relationship with pumps and their ever evolving sealing components.

One area, in particular, where I have gained considerable experience with sealing technology is through my efforts to assist end-users and manufactures achieve their business objectives. Early on in my career designing pumps, I would treat the mechanical seal as a little “black box”; a confusing set of springs, O-rings and other parts, and would focus my energy on the pump components such as bearings, impellers, shafting, etc. However, I quickly found that the mechanical seal was a critical component, likely the most critical, and that there are a number of seal technology variations available to users which can be confusing when attempting to address this area. By becoming involved in seal design and technology, I have been able to assist numerous pump manufacturers and end-users select the correct sealing technology for their pumping systems, whether it is for new applications or ones with reliability issues. I achieve a great sense of satisfaction by helping with both single applications or with upgrading an entire plant’s technology.

By working closely with end-users and analyzing their sealing issues, I have been able to gain a tremendous amount of insight into the contributing factors affecting pump performance and have been able to address these in either an application specific or plant-wide basis. End-users and equipment manufacturers have a wide variety of needs at each level of their organizations. In general, each group is looking for consistency, reliability and quality in both their products and their supplier relationships. By conducting a gap analysis on current practices and technology versus best practices and technology, I can identify areas of improvement. These gaps can then be assessed, prioritized and corrective actions can be implemented. It has been very gratifying to help improve rotating equipment reliability and save companies a significant amount of money. When you can double the reliability of rotating equipment in a plant, cost savings are often measured in millions of dollars.
PE: How often have you seen the industry change over the years?

Scott: As business is always evolving, and needs and expectations change, it is important that manufacturers and end-users keep up with their requirements. I have been witness to many significant technological advancements and progressive innovations since I first entered the industry. We have come a long way from the days of component seals, sleeved shafts, stuffing boxes and rubber lip seals. Although, I am still surprised to see these technologies commonly used. The most noteworthy change with regards to pump seals was the move from component to cartridge seals. Cartridge seals have, for the most part, eliminated the installation errors of mechanical seals, which used to be quite common; cartridge seals have become the seal of choice. Although component seals are still commonly used on small inexpensive pumps, cartridge single seals that utilize springs in their stationary components have become increasingly popular. Newer designs are using single piece seal rings to maintain better seal face flatness. With double seals, you see the use of tandem configuration seals as a platform of choice for greatest performance.

“By conducting a gap analysis on current practices and technology versus best practices and technology, I can identify areas of improvement. These gaps can then be assessed, prioritized and corrective actions can be implemented. It has been very gratifying to help improve rotating equipment reliability and save companies a significant amount of money. When you can double the reliability of rotating equipment in a plant, cost savings are measured in millions of dollars.”

With pumps, the biggest change I have noticed is the shift in focus towards improving a pump’s reliability and ease of use. Many pumps have enlarged seal chambers available to provide improved cooling and lubrication and are less prone to clogging but you still see seals being used in very narrow stuffing boxes that are compromising performance. 

Other notable changes I am currently witnessing, are the increased use of variable speed drives and the push to coat pump internals. As end-users become more total-cost conscious, they are starting to see the energy efficiency benefits of using variable frequency drives. It is very common to see a control valve being used to vary operating flows in a pumping system. If a variable speed drive is used, pumps can often operate closer to their best efficiency point (BEP) which improves their energy efficiency. By operating closer to the pump’s BEP, reliability of a pumping system can also be improved as a result of lower hydraulic loads on the pump. The use of coating on both new and rebuilt pumps, similarly, can prolong a pump’s efficiencies and lower its energy consumption.

PE: What do you see customers looking for today?

Scott: It depends on the customer of course. Large customers, that use a high volume of mechanical seals and pumps, are looking for low cost. Some companies choose to quantify that in low acquisition costs and others look at total costs.

Smaller customers sometimes require higher service levels and look for suppliers that can offer a number of different items. To these customers, having someone that can take care of a number of different needs helps. Service comes in different forms; receiving a quality product on-time, is first and foremost. Knowing what to order and how to install and operate the equipment, so it performs correctly, is important.

I have also noticed that more and more customers are seeking out services that can be offered directly by the manufacturer, locally or even in a more automated ways.

(Continued in Part Two.)
 

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