Are you planning to install a new gas line? This is a significant investment and you must ensure to follow your local codes including the correct pipe to use for natural gas.
When setting up your gas line, you will have the choice of galvanized pipe or black pipe. Each pipe has its pros and cons but many homeowners and professionals are divided over whether which of the two is the better choice. Can you use galvanized pipe for gas? Is black pipe safe?
If you want to make a solid decision about which pipe to use, you’ve come to the right place. In this article, you will find out everything you need to know about the suitability of galvanized pipe for gas. You will also learn about other close alternatives such as black pipe, commonly use in natural gas installation.
So, let’s jump in!
The Importance of Choosing The Right Piping for Natural Gas
Natural gas is one of the most cost-effective ways to keeping your house warm in winter, running the air conditioner, and operating the boiler. But, natural gas can be dangerous if you neglect your installation and fail to perform regular maintenance as needed.
Leaking is major concern when it comes to natural gas piping. A small leak in the pipe lead to a catastrophic fire in addition to impacting on air quality.
It is important to understand how your gas line works and to use the right piping materials to prevent costly problems such as corrosion leading to leaks, appliance breakdown, noise and air pollution, and high energy bills.
Different materials are suitable for gas piping but the two most common ones are black pipe and galvanized pipe. If you are installing a gas line for the first time, your local supplies store will typically recommend one of these two.
Ultimately, it is not a matter of picking one of the two—it is a good idea to consider the advantages and disadvantages to make a smart decision.
Should You Use Galvanized Pipe for Gas?
Before we talk about whether you can use galvanized pipe for gas, let’s first find out what we mean by galvanized pipe.
Galvanized pipe is a type of steel pipe coated with zinc. Steel on its own is prone to corrosion when exposed to water and oxygen. To slow down corrosion and increase the lifespan of steel pipes, manufacturers apply a zinc coating. The zinc coating does not last forever; it will wear off over time but this could be after many years of use.
You may have had that you should not use galvanized pipe for transporting natural gas. Some even say that it is illegal to use these pipes for gas, but is it? Well, the answer is yes and no.
Galvanized steel pipes get a bad rap because in the past, manufacturers used low quality zinc metal and inferior galvanizing methods. This caused the zinc coating to chip and the metal debris to block gas burners, regulators, and other appliance powered by the gas line. Of course, blockages cause inefficiencies in the gas line and eventually the whole installation stops working.
Modern galvanized pipes are built with quality in mind and do not have the same chipping problems as old pipes. You can therefore use galvanized pipe for gas without worrying about the zinc chippings clogging your piping system and appliances.
That said, piping regulations such as the International Residential Code (IRC) and Uniform Plumbing Code (UPC) prohibit the use of galvanized gas in underground transportation of natural gas. Galvanized pipe will eventually peel off and corrode when the steel comes into contact with oxygen and moisture. Corrosion weakens the pipes, leading to a potentially catastrophic gas leak.
Next, let’s compared the suitability of black pipe vs. gas pipe for use in natural gas installations.
Black Pipe vs Galvanized Pipe for Gas
Before we compare black pipe vs. galvanized pipe for gas, let’s find out what black pipe is. Black pipe, also known as malleable iron or black iron pipe, gets its name from its color (no surprises there). The black color is as a result of the iron oxide that forms when the steel is exposed to oxygen.
Black pipe and galvanized pipe are made from the same core material i.e. steel. The difference is that galvanized pipes are coated with zinc to prevent corrosion while black iron pipe is uncoated.
Like galvanized pipes, you should not use black pipe in underground natural gas installation. For such installations, local building codes in most areas require using a steel pipe that is factory-coated with a special, moisture-resistant, plastic material.
So, what is the best pipe for gas?
Black pipe is the best for gas installations. Because this piping does not have an extra coating, you do not have to worry about metal chippings clogging your gas lines and appliances.
That said, modern galvanized steel pipe is also a good choice for natural gas. This pipe does not have flaking issues and is therefore of a much higher quality than old galvanized steel. Still, you should check with your local codes.
Aside from the flaking issue, some home owners and professionals may shy away from galvanized pipe because of the cost. This pipe tends to be pricier because of the additional galvanization process.
Having said that, some home improvement stores sell black pipe for at a higher price. They take advantage of the fact that black pipe is the most preferred for natural gas pipe.
Why Black Pipe Is Commonly Used in Natural Gas Installations
There is a misperception that galvanized pipe cannot be used for gas. Others even say that using this pipe for natural gas is illegal. But, the truth is, this is no longer the case and only applied to old galvanized pipe. New galvanized pipe is built for longevity but most importantly, it no longer has the same flaking and clogging problems it had in the past.
Still, most homeowners and piping professionals prefer black pipe for natural gas. Black iron pipe has some natural advantages that make it the best pipe for gas installation. Let’s look at some of these advantages:
1. Seamless
A big difference between black and galvanized pipe is that black pipe comes without a seam. The seamless nature makes black iron pipe leak-proof, ensuring safety when transporting natural gas. Black iron pipe is also heat resistant.
2. Less expensive
Black iron pipe is generally cheaper than galvanized pipe of the same diameter. The extra galvanization process adds to the cost of production, making galvanized pipe slightly costlier than black iron pipe. If you are on a budget, black pipe for gas might be a better choice.
3. Local regulations
The Uniform Plumbing Code and the International Residential Code do not prohibit the use of galvanized pipe for gas. But, some local regulations make it illegal to use galvanized pipe. Due to such prohibitions, many homeowner and professional opt to use black iron pipe in natural gas installations.
4. Use of galvanized pipes in water systems
Most homes already use galvanized steel pipes in their water piping system. So, using galvanized pipe for gas can bring in some confusion as to which is which. No one wants to mistake their natural gas line for their water line or vice versa. If you opt to use galvanized pipe for gas, a best practice is to make it with yellow paint to distinguish it from the water piping.
Is it Safe To Use Black and Galvanized Pipe in the Same Installation?
Another concern that homeowners have is whether you can join black and galvanized pipes in the same natural gas installation. The answer is: It depends.
Local codes generally prohibit joining black iron and galvanized steel pipe because a chemical reaction occurs when the two metals interacts. The reaction can cause corrosion and increase the risk of a gas leak.
Using black iron and galvanized pipe is generally safe if the connection is above-ground i.e. inside your house. The chemical reaction between the two pipes is extremely slow and insignificant.
But, the case is different for underground installations. It is best to avoid connecting galvanized and black pipe underground because the presence of moisture and oxygen can lead to rapid corrosion of the pipes, potentially causing gas leaks.
Summary: Can You Use Galvanized Pipe for Gas?
Galvanized pipe gets a bad rap because the zinc coating chips and clogs gas lines. But this is old news. Modern pipe is of a better quality and does not have these chipping problems. So, unless your local codes prohibit it, you can use galvanized pipe for gas. Just be sure to mark your gas lines with a yellow paint to distinguish the galvanized water piping from the galvanized gas pipe.
That said, black iron pipe is the most preferred pipe for natural gas. The pipe is less expensive, already in use in most homes, and is seamless, making it less prone to gas leaks. If you plan to sell your home in future, your best bet is to use black pipe for gas and to avoid connecting galvanized pipe with black pipe as the corrosive reaction between the two pipes can potentially cause leaks in the piping.