I started out in the business working for a manufacturers’ rep on the Isle of Long. We represented a dozen or so companies in the plumbing and heating world. The plumbing guys and the heating guys worked in different rooms, and neither group knew much about what the other was up to.
I began as an assistant to my father. We processed the orders for NIBCO and, of course, on my first day, I asked him what a NIBCO was.
“It’s a word that stands for Northern Indiana Brass Co., kid,” my father said. “N is for Northern. I is for Indiana, B is for Brass. CO is for Company.”
I bobbled my head.
“You should know that,” he said.
“Okay,” I said, feeling quite dumb.
“What does B&G stand for?”
“Bell & Gossett,” he said. “But that’s heating, not plumbing. The other guys work with that stuff. We’re plumbing. Remember that.”
“What sort of bell and what’s a gossett?” I said.
My father stared at me for a while and then said, “Go ask the heating guys. But do it on your own time.”
What’s in a name?
So I did. And after a well-deserved eye-roll, the head heating guy explained about the two men who started the company a long time ago.
“They were Mr. Bell and Mr. Gossett,” he said. “Bell didn’t stick around for long,” he said. “Anyway, they’re both dead now.”
We also represented Lawler. That was plumbing. The Lawler guy was on the road most of the time. He wore polyester suits and smiled with his mouth but never with his eyes. I asked him what a Lawler was one day when he stopped by to drop off some orders.
“That’s the owner’s name. His first name is Jim. He makes mixing valves,” he said.
“What do they mix?” I asked.
“Hot and cold water,” he said.
“So people won’t get burned,” he said. “You’ll learn.”
I bobbled my head.
Then Blake arrived on the plumbing side of the building and our company decided that I should be the Blake guy. I never learned who Blake was, but they made drains and carriers for wall-mounted toilets. This was easier for me to understand than mixing valves because with Blake, the only moving parts were wet and smelly. Blake products just sat there or hung there and waited for something brownish to arrive.
The problem, though, was that Blake used considerably more iron in their products than any of their competitors, which made it very strong, but also more expensive. Most contractors didn’t give much thought to the longevity of drains and carriers, so on most days they bought on price alone. As a result, Blake bit the dust, and that’s when the company decided I should leave plumbing and become a heating guy.
They moved me into the other room and my training went something like this:
“B&G doesn’t make pumps, Dan. They make circulators. Don’t call them pumps.”
“What’s the difference?” I asked.
“Pumps pump. Circulators circulate,” the head heating guy said.
I bobbled my head, intrigued by the Zen of it all.
Time went by, and I finally learned more by reading and asking lots of annoying questions. I learned that a bicycle pump is a pump. So is the machine at the gas station that puts the gas into your vehicle’s tank. Pumps pump. Got it.
The guy who delivered our fuel oil told me oil burners also have pumps.
“The pump pumps the oil into the nozzle,” he said. I had to ask him about this because we didn’t sell boilers or any sort of burner. That meant no one at our company knew much about either boilers or burners. We were specialists.
“What makes it a pump?” I asked the oil guy.
“When it comes on,” he said. “You’re going to get a big increase in pressure at its discharge. Just like you get with a bicycle pump. You can depend on it. The pressure will show up on the oil pump’s outlet, and it’s always going to be higher than what you see on the pump’s suction side. The factory designs them that way. It will always be that way no matter what. That’s how you burn oil.”
I bobbled. “But what’s a circulator then?” I asked. “What makes them different?”
He wasn’t sure, but he knew that some people called them that.
“I still call it a pump most of the time,” he shrugged. “It’s what the guys at the wholesaler understand. Pumps.”
After reading more and asking hundreds of questions of anyone who would stand still long enough, I learned that a circulator is different because it works within a closed, pressurized heating system. It doesn’t have to lift the water to the top of the system because the water is already up there. The circulator just circulates the water.
It’s like the motor on a Ferris wheel. The weight of what’s going up balances the weight of what’s coming down. The water is turning round and round, just like a big wheel. And to get it going, all the circulator has to do is move the water that’s inside of itself into its discharge pipe. And since you can’t compress water, when the circulator moves even a little bit of it, the rest of the water in the system also moves.
The water is like a bicycle chain. Move one link on the chain and you move them all. I’m no engineer, but I sure could see that in my mind’s eye.
I learned that we call the inlet to the impeller the “eye.” It’s similar to the eye of a hurricane, but much friendlier. The impeller spins and creates centrifugal force. The water flows from the impeller’s eye along the vanes that reach out from the eye, creating a higher pressure at the tips of the vanes (which is also the outer edge of the impeller) and a lower pressure at the eye.
I learned to call this difference Delta-P, which stands for difference in pressure. A difference in pressure between any two points will always cause flow. I knew that instinctively and now I had words for it. I also had pictures in my head. I watched the weather guy on TV. He talked about a low-pressure system moving in. He said it was going to get windy because when there’s low-pressure anywhere, air from a high-pressure location will rush over to fill in the hole. Think about a tornado. It’s a ridiculously violent version of an impeller.
I learned that an impeller spins the water and directs it toward the outlet of the circulator, which is always a bit narrower than the inlet of the circulator. Have you ever noticed that? Don’t look at the size of the flange; look at the shape of the waterways entering and leaving the impeller. The moving water experiences centrifugal force like at an amusement park and suddenly has to race through that narrow exit. And it speeds up as it does that because water is not compressible. You can see all of this if you have gauges on the circulator, or a good imagination.
But the thing about a circulator and what makes it different from a bicycle pump, or an oil pump or the pump on a fire truck is it doesn’t have to show an increase pressure at its discharge side. It just has to show a difference in pressure from one side of the circulator to the other side.
This means the discharge side can stay the same as long as the suction side drops. You can see this if you pipe gauges on either side of the circulator. How the pressure difference appears on the gauges will depend on the location of the compression tank within the system. The tank is a point where the pressure will always be constant because the circulator can neither add nor remove water from the tank. A circulator takes its orders from the compression tank. But that’s a story for another day.
So, as that long-gone heating guy once told a much younger me, “Pumps pump; circulators circulate.”
And that’s why we have different names for them.
But you know what? Even though I’ve been saying “circulator” for most of the past 50 years, I do slip up from time to time and say “pump” instead.
Because that’s what the guys at the wholesaler call it.