And What Do You Do?

Those in the business of mechanical seals often must travel. It seems that there are always conferences to attend and classes to teach in addition to the attention and assistance needed by customers. Add to these trips a few internal business meetings and travel becomes a significant part of life. For those in this business, an awkward but frequently asked question by a new acquaintance is “… and what do you do?”.

I’ve struggled with this question for some time. Of course, people don’t want a lengthy answer and, except for a small (but elite!) group, no one knows what a mechanical seal is. On the other hand, most people have some concept of a pump. Therefore, any explanation of a mechanical seal to an unenlightened acquaintance usually begins by pointing out that the seal is the component that prevents leakage around the pump shaft. The mechanical seal industry should be pleased that most people don’t know about their product. It is to the credit of that industry that their devices work so well as to be taken for granted. In fact, most people have never even considered the challenge of sealing a rotating shaft.

As an engineering student, I distinctly recall wondering how to prevent leakage around a rotating shaft. I knew about close clearances, lip seals, O-rings and packing but couldn’t imagine a mechanical seal. Perhaps it is because I couldn’t invent this device that I am so fascinated by it. Here is a gadget – no, a machine – that incorporates virtually every facet of the art and science of engineering. Stress, strain, thermodynamics, heat transfer, fluid flow, statics, dynamics, mathematics, tribology – the list builds to become the engineering curriculum – are all necessary to understand the design and performance of the mechanical seal. The interrelationships of these phenomena are so complex that powerful computers using finite element analysis and computational fluid dynamics can only approximately simulate the performance of a seal. Think about the recent advances in sealing technology that have reduced or eliminated leakage while improving reliability. Consider the precision required to manufacture the components of this machine to thousandths, even millionths, of an inch and the industry that can accomplish this feat routinely. Praise the skilled technicians who assemble, install and operate this machine. What an industry!

But there is still the question, “… and what do you do?”, because, to the mechanical seal aficionado, the pump is a mere container that holds his pride and joy. We look with disdain on the sealless pump and dream about a pumpless seal. We want to be identified with our machine instead of a component of some other machine. Many other people in the mechanical seal industry share my frustration with this question. They’ve told me stories of lifelong friends, even family, who never knew or understood their business. We laugh about our attempts to describe mechanical seals to those we meet while traveling.

My favorite story about this frustration begins with a good friend telling me that he had long since given up on explaining mechanical seals. When asked, “… and what do you do?”, he simply replied that he was a traveling shepherd. He said everyone could identify with shepherds. His fabricated vocation had led to interesting conversations about the advantages and disadvantages of working outdoors as well as the responsibilities of maintaining a flock that was surrounded by enemies. My friend could wax eloquently on coping with solitude and complain bitterly about the lack of well-trained sheepdogs. He spoke of the various breeds of sheep and the difficulties of finding a good shepherd’s crook. He explained that sheep were not as simple as they appeared and that years of training and many skills were required to be a good shepherd. He believed that, even in the face of advancing technology, there would always be a place for sheep and therefore shepherds. With a smile, he would conclude that people were much more interested in and sympathetic to a shepherd than to a mechanical seal salesman.

I can’t tell the shepherd story as well as my friend so I’ve resorted to simply replying that I’m an engineer and then watching their eyes glaze over.

The Recording

“Now that I’m a consultant, I wonder if I could get a copy of that recorded message.”

We were working on the details of a thorough class about pumps and seals and my mind was on the lesson plan – not conversation. “Message? What message?”

“I don’t know what to call it, but you know the one I’m talking about. All the pump and seal companies use the same one. I just want a copy.”

Knowing my customer, friend and now co-instructor, I should have realized that I was being taken in but my mind was still on the lesson plan. “I have no idea what you’re talking about.”

With a sincere look, in a serious tone, he delivered his punch line: “When I had rotating equipment problems, I’d always be referred to someone in the engineering department. The engineer would listen politely as I described the equipment, the problem, my observations and our attempts at a solution. Then he’d reach over and — I swear I could hear it — punch the button for the recording. ‘We have thousands of those (whatever) working reliably in severe services all over the world. I’ve been working with them for years and never heard of anything even remotely resembling the problem you described.’”

He finished me off with a grin, “I just want a copy of that recording.”

Too late, I caught on and attempted a comeback. I said that the recording was, of course, proprietary and, even if it weren’t, was copyrighted and therefore couldn’t be copied. Trying again, I told him that they required a special machine to play the recording. Desperate now, I pointed out that they required special training as a qualification to use the recording. He kept his grin, knowing that he’d pulled a good one on me, and that my attempts at a comeback were inadequate. Finally, I had to give in and join the laughter. At least I had made his day.

Not even two weeks later I heard myself telling a customer “That’s a new one on me.” (No, I didn’t use a recording.) Suddenly, I recalled my friend’s joke and had to laugh.

Is “the recording” really used that often? Probably so – and if you think about it, you can easily see why. Anyone with a few streaks of grey in their hair knows why a young engineer needs the recording: There is a lot to be learned in our business. But there is a legitimate reason that even an experienced rotating engineer might need the recording: There are just too many permutations and combinations for anyone to have seen them all. Perhaps this is just another way of saying that we are all too young!

Especially in these times of computerized information systems, there are many databases of rotating equipment application experience. End users of rotating equipment often want to see an experience list before buying new equipment. Manufacturers have set up databases to satisfy customers and optimize their own procedures, inventories and marketing. End users also have their own databases for maintenance and inventory. With all these databases, finding duplicate experiences should be easy but it isn’t. Just try it sometime.

Thinking of computer databases, have you ever tried to find something specific in one? As you’d expect, the more specific the query, the fewer records to be found. Nevertheless, making the query so specific that no matches are found is surprisingly easy. When this happens, the computer plays its own recording, “No records found.” Somehow, probably because it is a computer, this is more acceptable.

The current API 610 data sheet for pumps is five pages long and, depending on how you count them, contains hundreds of entries. The matching API 682 data sheet for seals is also five pages. Of course, some of this data is simply informational and some is duplication. Even so, it is apparent that the experienced developers of these data sheets believe that a lot of information is necessary to describe a pump and seal application properly. With so many parameters required to describe an application, it should come as no surprise when even the most experienced rotating equipment engineers discover “No records found” in their mental database.

King Solomon said that there was nothing new under the sun but, then again, he was not a rotating equipment engineer. In the broadest sense, we can accept his truth; however, in the narrow field of rotating equipment, there are many new and exciting machines, components and applications – not to mention combinations. The challenge of rotating equipment is evaluating the new as much as it is learning the old.

That recording does come in handy.

Definition of a Pump

A pump is a device designed to provide a housing for a mechanical seal.

Seal Humor