Posted on: November 21, 2016
By: Alan O'Neill
Posted in: Plumbing
Black iron pipes are steel pipes that are cut to length, threaded, and used in applications such as gas lines and water supply lines. They are primarily used for natural or propane gas lines, so when you have to work on your gas line, it’s essential that you know how to deal with black iron piping.
Teflon tape or pipe dope can be used to create a seal on black iron pipe.
Hold the pipe in a pipe vise on a stand and cut with a pipe cutter with rotary cutting blades. It is recommended that you use a high-quality cutting oil to help protect the pipe cutter.
Once the pipe is cut to length, deburr or shave down the cut end to remove the sharp ridge that will be present when the pipe is finished being cut. Use a lot of cutting oil to prevent damage to the cutter and the threads. A large piece of cardboard or plywood under your cutting and threading area will save you a lot of cleaning later. Alternatively, use a bucket with a large screen strainer under your cutting area to catch excess oil, which will allow you to re-use it later on.
The pipe must be threaded to make the proper connection. If you’re lucky, you may find the pipe in the required length at a plumbing outlet or hardware store. Threading is accomplished with a pipe threader. Use the proper die for the size of the pipe. Fit the die over the end of the pipe, and turn the handle a half turn at a time to cut the thread. Use a good quality cutting oil to protect the die. Continue threading until the thread is the thickness of the die. The thread will be cut on a taper when finished, providing a better seal. Stand the pipe on end when done to dislodge any pipe cuttings. Wipe the threads with a rag. Be careful here – the pipe threads are sharp.
Black iron pipes are joined using fittings and connectors. In a typical gas line installation, Teflon tape or pipe joint compound should always be used on the threads to ensure there are no leaks.
If using a pipe thread sealant tape, wrap it around the threads and insert into the fitting. Make sure you wrap the Teflon tape in the correct direction; facing the end of the pipe, you wrap in a clockwise direction. You should wrap the tape around the threading at least four times, but no more than six or seven times.
Alternatively, you could use pipe joint compound, also known as pipe dope, as an adhesive on the threading to ensure a tight connection. Pipe dope is applied with a brush, small piece of wood, or a rag. It is applied on the threaded end of the pipe and inside of connection fittings before the two pieces are attached to each other. The adhesive dries over time and slightly expands to create an airtight seal between the pipe and the connection fitting where the compound has been applied.
Hand tighten the pipe, then using two pipe wrenches – one on the pipe and the other on the fitting – tighten the connector. If you’re finding the pipe is too loose, you may have to re-cut it. Read more.
I have tightened them hand tight and then put a small nipple on the elbow to turn it again and it starts to get pretty snug where I may not be able to make another full revolution without tools but no tools will fit. They can be moved when I attach the longer pipe to them if I don’t back the inside up with a wrench while tightening the outside. I used Pro Dope and usually tighten very tight and never have leaks. Call (713) 812-7070 us for your home service and repair needs.
For more related articles and info visit Blog.