Earlier this year, we started selling a range of black iron pipes and fittings in our online store. Since then, we’ve learned that many shoppers know very little about this premium material. In short, black iron pipes are one of the best options for existing gas pipes. It is strong, easy to install, corrosion resistant and maintains an airtight seal. The black coating helps prevent corrosion.

Black iron pipe used to be used for water pipes, but since the advent of copper, CPVC and PEX it has become more popular for gas. It’s a great option for fueling up for two reasons. 1) It’s sturdy, 2) It’s easier to put together. Just like PVC, black malleable iron uses a system of pipes and fittings that are mated together with a compound, rather than welding. Despite its name, black iron pipes are actually made from a low-grade “low carbon steel” compound. This gives it better corrosion resistance than traditional cast iron pipes.

Characteristics of black iron pipes
Since this post is all about black iron pipes and fittings, we’ll dive into some of its features and characteristics. It’s important to be knowledgeable when it comes to your home’s plumbing.

Black Iron Pipeline Pressure Limits
“Black iron” is a term that usually refers to a type of black coated steel, but many different types of black iron pipe exist. The main problem with this is that all black iron pipes adhere to very few standards. However, they are both designed to handle natural gas and propane gases, which are typically kept below 60psi. If installed correctly, the black iron pipe must meet standards to guarantee a pressure rating of at least 150psi.

Black iron is stronger than any plastic pipe because it is made of metal. This is important because gas leaks can be fatal. In the event of an earthquake or fire, this extra intensity could cause potentially deadly gases to leak throughout the home.

Black iron pipe temperature grade
Black malleable iron pipes are also strong when it comes to temperature ratings. While the melting point of black iron pipes can exceed 1000F (538C), the teflon tape holding the joints together can start to fail around 500F (260C). When the sealing tape fails, the strength of the pipe doesn’t matter because the gas will start leaking through the joint.

Fortunately, teflon tape is strong enough to withstand any temperature the weather causes. In the event of a fire, the main risk of failure arises. But in this case, the occupants of any home or business should already be outside when the gas line fails.

How to Install Black Iron Pipe
One of the main advantages of black iron piping is its malleability. This means it can be threaded effortlessly. Threaded pipe is easy to use because it can be screwed into the fitting without having to be welded. As with any system with threaded connections, black iron pipes and fittings require Teflon sealing tape to create an airtight seal. Fortunately, sealing tape and duct paint are inexpensive and easy to use!

Assembling a black iron gas system requires a little skill and a lot of preparation. Sometimes pipes are pre-threaded to specific lengths, but sometimes they must be cut and threaded manually. To do this, you have to hold a length of pipe in a vise, cut them to length with a pipe cutter, and then use a pipe threader to create a thread at the end. Use plenty of thread cutting oil to avoid damaging the threads.

When connecting a length of pipe, some type of sealant must be used to fill the gaps between the threads. Two methods of thread sealant are thread tape and pipe paint.
Teflon Tape Thread Tape Thread Sealing Tape

How to use thread tape
Thread tape (often called “teflon tape” or “PTFE tape”) is an easy way to seal joints without messing up. Application takes just seconds. Wrap thread tape around the external threads of the pipe. If you’re looking at the end of the pipe, wrap it clockwise. If you wrap it counterclockwise, the act of screwing on the fitting may push the tape out of place.

Wrap the tape around the male threads 3 or 4 times, then screw them together as tightly as possible by hand. Use a pipe wrench (or a set of pipe wrenches) for at least one more full turn. When the pipes and fittings are fully tightened, they should be able to withstand at least 150psi.
store pipe tape

How to use pipe paint
Pipe paint (also known as “joint compound”) is a liquid sealant that penetrates between threads to maintain a tight seal. Pipe paint is great because it never dries completely, allowing unscrewed joints for maintenance and repairs. One downside is how messy it can be, but often the duct paint is too thick to drip too much.