In this episode, Dan Holohan shares the tale of how nominal pipe sizes came to be, as well as some comical work stories.
I called the plumber because there’s immediacy to plumbing; and I’m old enough to know that it’s best for me not to touch pipes. To each his own trade.
The company sent Vadim, the head guy, and Alex, the helper. The problem was the last bit of copper tubing in our Long Island house. Long Island water has a way of eating green holes along runs of copper tubing, mainly on domestic-water lines, and we had been spending the last few years banishing it from our house and replacing it with PEX. This, of course, was expensive, but not as expensive as having to replace the ceilings and kitchen cabinets every few years. This time, it was the 30-year old copper that fed our washing machine on the second floor.
Vadim and Alex sound like Boris and Natasha in those old Rocky and Bullwinkle cartoons, so I was doing my best to follow along when they spoke to me in English.
Vadim leaned and looked at the pipe inside the wall I had already opened and said something in Russian that made the copper cringe. He sent Alex down to the truck to get some PEX. I followed him down and sat on the couch, the place where I was sure Vadim wanted me to be.
A few minutes later, Vadim came halfway down the stairs and said, “You close water.” I got up and headed for the main valve. Thirty minutes after that, Alex came down the stairs with some red- and blue PEX, which I assumed was what was leftover.
“Ufon war,” he said as he approached the closed storm door. I got up and opened the door for him. He gave me a confused look in passing and I went back to the couch.
Ten minutes passed and Vadim again appeared, halfway down the stairs. “You open water?” he said, looking aggravated. “Alex tell you open water. You open water.”
“I thought he said I should open door,” I said.
“Why he say that? He can open door himself.”
“He was carrying the PEX,” I said.
“Pfff,” Vadim said. “PEX not heavy.”
I opened the water and Vadim then invited me to see what he had done. It was perfect. And I appreciate that because piping is not easy, no matter the language.
The Wallies at HeatingHelp.com were talking about pipe recently. One guy asked a question about why some pipe sizes are skipped. “For instance,” he said. “Why are 5- inch and three-and-a-half inch skipped?
A Wallie said, “Five-inch isn't skipped. We buy it all the time. It’s the same with 3-inch. After you get to six-inch, I believe it goes every two inches. So, 8-inch, 12-inch, etc. The only one I've heard about that used to be made but is now gone is 3-1/2-inch."
A New-York-City Wallie chimed in, “You see 3-12-inch in old buildings. I once saw a seven-inch pipe in an old apartment building.”
We were on a roll now. Another guy wondered why they developed 1-1/4-inch pipe. “It’s the only quarter-size pipe I’ve ever seen.”
I remembered back to an article my colleague Julius Ballanco wrote in 2006 about how nominal pipe sizes came to be. He had the answer, and it’s a good one. This is from PMEngineer:
“The person directly responsible for the nominal pipe size was a gentleman by the name of Robert Briggs. Briggs was the superintendent of the Pascal Iron Works in Philadelphia. In 1862, he wrote a set of pipe specifications for iron pipe, and passed them around to all of the mills in the area.
“Realize that in 1862, this country was engaged in the Civil War. Each pipe mill made its own pipe and fittings to its own specifications. Briggs tried to standardize the sizing, which would also help the war effort. The pipe and fittings would be interchangeable between mills. This was rather novel in 1862.
“The pipe standards went on to become known as the “Briggs Standards.” They eventually became the American Standards, and finally the standards used for modern-day pipe.
”The current ASTM A53 Steel Pipe Standard uses basically the Briggs Standard for pipe sizes half-inch through four-inch. You will notice that after four-inch the pipe starts to get closer to the actual dimension used to identify the pipe.
“So, you are probably asking, where did the sizes come from? Well, they were the sizes of the dies used in Pascal Iron Works. Briggs made everyone adjust to him. Hence, the name “nominal” pipe size came about, meaning ‘close to’ or ‘somewhere in the proximity of' the actual dimension’.”
So there you go.
And then the conversation turned to the length of the pipe. “Why is 21 feet the standard length of iron pipe?” a Wallie asked. “Does it have to do with that being the maximum length that would fit on an old truck bed?”
This got me thinking about a story an older contractor told me about what his apprentice did to him one day. “I pulled the pipe out of the truck and set the end on my shoulder,” he said. “I can’t recall the exact pipe size, but it was big enough for me to remember what happened next.”
“Well, the kid was supposed to grab the other end of the pipe when it cleared the truck and put it up on his shoulder. He wasn’t the biggest kid I ever worked with.”
“Oh, no. Please don’t tell me.”
“Yep, the pipe slipped and hit the concrete.”
“What’s that like?”
“I’m still quivering,” he said.
It turns out the 21-foot limit for iron pipe had nothing to do with the truck. The reason manufacturers settled on 21 feet is because they learned that’s the longest length that could hold the heat to produce a good weld along the seam, while also allowing the pipe to form its shape.
To each his own trade, right?
“I am a retired plumber,” another Wallie said. “When I was an apprentice we had a job at a beer warehouse. It was my first day on the job and the journeyman had called in sick. The yard with all the pipe was fully stocked and all the trenches were dug. I was installing the no-hub, cast-iron waste pipe in the office area. I looked at the plans and figured out where everything went. So I started to string out the pipe for the mains. I hauled about 20 lengths of heavy, cast-iron pipe from the yard, and up and over mounds of dirt. Then I got the fittings. I threw the first 4-inch wye fitting into the ditch and next to the pipe I’d just lugged in. That’s when I discovered that cast-iron pipe also comes in 5-inch.”
Which makes me think of this old proverb: Some days you eat the peanuts. Some days you eat the shells.
But let’s conclude with the wonders of copper. This Wallie was appropriately scratching his head when he wrote, “Copper tubing is sold in nominal sizes Type K, L, and M for plumbing and heating. There is also DWV copper tubing for plumbing drain, waste and vent.
“DWV, K, L, and M all have the same outside diameter for a given size. Only the wall thickness varies.
“In air conditioning and refrigeration, they sell the same tubing in OD sizes, which makes more sense and I think that’s the way all copper should be sold. Why don’t they make it less confusing? Did Robert Briggs get his paws on copper tubing as well?”
I don't think they were making standardized copper tubing in the 1860s, but you never can tell with copper. I’m just glad the last of it is finally out of our house. Now I can safely “ufon war” and not be concerned about the PEX turning green and sprouting more leaks than a Urology convention.
And as to why they label copper tubing K, L, and M, I like to think the person who came up with that had three daughters: Karen, Louise, and Mary, and being a good dad, he named the tubing after his little angels.
Karen. . . was the most difficult, of course.
I hope you enjoyed that tale. Thanks for being here. It means a lot.