Hi there, my name is James and I'm one of 550 employee investors here at Gregg Distributors.
I'd like to welcome you back to Gear up with Gregg's.
Today we're going to talk about the dark side of the pipe fitting family... black iron!
While black iron pipe is used for many applications, including air, water, oil, and gas, in Canada
it's most commonly used for natural gas and propane.
But why?
Well, black iron pipe is strong, and despite its name, it is actually made of a low-grade
mild steel compound, not iron!
This steel allows the pipe, and its fittings, to have more strength than its copper, aluminum,
or PVC counterparts.
It is commonly used to transport gas as the extra strength in this metal pipe could be
what keeps potentially-deadly gas from leaking throughout a home!
While black iron is a low-pressure pipe, the temperature rating is where this metal really shines.
Black iron pipe can withstand temperatures of over 538ºC and these fittings are NPT threaded.
What's an NPT thread?
Well, it stands for National Pipe Tapered and these common fittings seal by a wedging
action, which makes for easy installation.
If you want to know more about NPT thread type, check out the first module of our Heads up for Hosers series.
It's all about NPT thread identification and installation!
There are three main types of black iron pipe fittings we carry here at Gregg's: malleable
iron fittings, forged steel fittings, and seamless fittings.
Malleable iron fittings are made for light industrial and plumbing use up to 300 psi.
These common fittings are more ductile, which means that they are able to be deformed without
losing toughness or becoming brittle.
This makes them great for industrial use.
Forged fittings are made of carbon steel, stainless steel, or nickel alloy.
The forging process involves heating a piece of carbon steel and molding it into the desired
shape, which creates a stronger fitting than casting.
Finally, we have seamless fittings.
These fittings are made directly from a section of seamless pipe material by applying heat and pressure.
Their design allows them to withstand greater pressures and they won't crack under an extreme load.
But we can't talk about black iron fittings without talking about nipples.
Funny name aside, nipples are often used in plumbing,
and other hydraulic applications as adapters.
The most basic type, a barrel nipple,
is a short length of pipe with male pipe threads at both ends.
These threads are for connecting other fittings.
These nipples can range anywhere from
1 - 1/2" to 60" long, not including the threads.
If you have a nipple
but there's no bare or unthreaded pipe between the two connecting ends,
you know you've got a close nipple.
With close nipples, the connected fittings come very close to touching one another,
and barely any of the nipple can be seen between them.
Some construction sites require this kind of tight placement, but sometimes, close nipples can be difficult to work with.
This is because unscrewing them requires a tight hold on part of the threaded area, which will damage the threads.
Now, as I said earlier, black iron pipe seals through a wedging action, but they also need
a sealant to create a leak-proof seal.
Luckily, sealing tape and pipe sealant are inexpensive and easy to apply!
But be careful!
You need to be sure you're selecting a sealant that's compatible with whatever material you're
moving through the pipe.
Sealing tape, commonly referred to as Teflon tape or PTFE tape, is a simple way to seal
joints without making a mess.
PTFE can only withstand temperatures up to 260C, but that's more than enough to handle
anything nature can throw at it.
But best of all, it only takes a few seconds to apply!
Your other option is pipe sealant, also known as joint compound or pipe dope.
This is a liquid sealant that oozes between threads to maintain a tight seal.
Pipe sealant lubricates while it fills in all the microscopic imperfections in a thread.
However, the downside to pipe sealant is that it can be quite messy compared to sealing tape.
One more thing that's important to keep in mind with pipe is the schedule.
Pipe schedules relate to the thickness of the pipe wall,
and the most common schedules are 40 and 80.
As the number increases, so does the wall thickness.
For instance, a 1" schedule 40 pipe will have a wall thickness of 0.133"
While a 1" schedule 80 pipe will have a wall thickness of 0.179"
However, while the schedule number can be the same for pipes with different outside diameters,
The actual wall thickness will vary.
So, the best way to see the relationship between pipe size, schedules and wall thickness,
Is to refer to a conversion chart like this one.
Another thing to keep in mind is that the nominal pipe size, or NPS,
Represents the approximate inside diameter of the pipe.
That's because if the schedule number on a size is changed, it affects the inside diameter,
but not the outside diameter.
When pipes were first made, they were measured from their inside diameter.
However, when different applications called for higher pressures, the size of the thread
could not be changed, since the pipe had to work in all the same situations.
So, they increased the wall thickness!
For example, a 2" nominal pipe will always have an outside diameter of 2.375", however,
depending on the strength of the pipe, the wall thickness could be either 0.154" or 0.218".
Now, we know black iron fittings come in a variety of sizes and styles, from tees to elbows to plugs.
Each fitting has its own use and application, and we'd be more than happy to help you find
the best fit for your job.
So feel free to give us a call, or you can visit our website at greggdistributors.ca.
Remember, if you want more great content like this, be sure to hit that subscribe button and notification bell.
That way, you'll know when we've got a new video!
Or, you can leave us a comment and let us know what your preference is, pipe sealant or sealing tape.
Again, I'm James and thank you for joining us on Gear up with Gregg's.