What is a black iron pipe?

   

Earlier this year, we began selling a line of black iron pipe and accessories in our online store. Since then, we've learned that many shoppers know very little about this premium material. Simply put, black iron pipe is one of the best options available for gas piping. It's strong, easy to install, corrosion resistant and maintains a gas-tight seal. The black coating helps prevent corrosion.


Black iron pipe used to be commonly used for water pipelines, but since the advent of copper, CPVC and PEX, it has become more popular for gas. It's a great choice for gas for two reasons: 1) it's strong and 2) it's easier to put together. Just like PVC, black malleable iron uses a system of pipes and fittings that work together with the compound, rather than welding. Despite its name, black iron pipe is actually made from a lower grade of "mild steel" compound. This gives it better corrosion resistance than traditional cast iron piping.


Black Iron Pipe Characteristics

Since this article is all about black iron pipe and fittings, we'll dive into some of its features and characteristics. It's important to be knowledgeable when it comes to the plumbing in your home.


Black Iron Piping Pressure Limits

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


Black iron is stronger than any plastic tubing 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 strength could result in a potentially fatal gas leak throughout the house.

Black Iron Pipe Temperature Ratings

Black malleable iron pipe is also strong when it comes to temperature ratings. While black iron pipe may have a melting point in excess of 1000F (538C), the PTFE tape that holds the joints together may begin to fail at around 500F (260C). When the sealing tape fails, the strength of the pipe is irrelevant because gas will begin to leak through the joint.

Fortunately, Teflon tape is strong enough to withstand any weather-induced temperature. The main risk of failure arises in the event of a fire. 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 pipes

One of the main advantages of black iron piping is its malleability. This means that it can be threaded effortlessly. Threaded pipe is easy to use because it can be screwed into fittings without having to be soldered. As with any system with threaded connections, black iron pipe and fittings require Teflon sealing tape to create an airtight seal. Fortunately, sealing tape and pipe coatings are inexpensive and easy to apply!

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

When connecting a certain length of pipe, some type of sealant must be used to fill the gap between the threads. The two methods of thread sealant are thread tape and pipe coating.

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 making a mess. Application takes only a few seconds. Wrap the threaded tape around the male threads of the pipe. If you are looking at the end of the pipe, wrap clockwise. If you wrap counterclockwise, the action of screwing on the fitting may push the tape out of place.

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

How to Apply Pipe Coating

Duct coating (also known as "joint compound") is a liquid sealant that penetrates between the threads to maintain a tight seal. Duct coating is great because it never dries completely, allowing the joint to be unscrewed for maintenance and repair. One drawback is how messy it can be, but usually duct coating is too thick to drip much.

Duct coating usually comes with a brush or other type of applicator. Use it to completely cover male threads in a uniform coat of sealant. Not applicable to female threads. After completely covering the male threads, screw the pipe and fitting together, just as you would with thread tape, using a pipe wrench to finish tightening.

Some plumbers recommend thread tape with a coating of pipe dope on top, so if you can't decide which you prefer, it's worth a try! For more detailed information on installing black iron piping, read this article.

Black Iron Fittings

In this article, we focus on black iron pipe, but fittings are an important part of any black pipe gas system. pvc Fittings Online sells a variety of black malleable joints and fittings (short, pre-cut, pre-threaded pipe lengths) at great prices!