Types of Copper Piping

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Copper piping is a popular choice for plumbing because it's durable, easy to install, and resists corrosion. It has been used as water supply lines in homes for decades. If you're looking to replace your copper pipes or want to know what type of copper pipe you have in your home, then you're in the right place. Copper pipes can be manufactured as soft or rigid copper and offer excellent corrosion resistance and reliable connections.

Copper pipes are made from pure copper that has been melted down into liquid form and poured through a mold. The molten metal hardens as it cools inside the mold. Once cooled, the rough exterior of the pipe is removed by grinding or sanding so that only smooth lines remain. 

Copper Pipe Sizing

The actual outside diameter of rigid copper type is always 1/8 inch larger than the normal size, or what the pipe is called. The inside diameter of the copper pipe is determined by the wall thickness of the pipe, which varies by the pipe type. The internal or external fluid pressure may determine the type of copper piping specified for any application, the installation, the service conditions, and the local building code requirements.

Here are the common types of copper piping:

Type K Copper Pipe

Type k copper type has the thickest wall of all the common types. It's used for water distribution, fire protection, oil, HVAC, and many other applications in the construction industry. Type k pipe is available in a rigid and flexible form and can be used with flared and compression fittings.

Type K Coppe Pipe
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Copper pipes of the same type and size all have the same outside diameter, allowing them to use the same fittings for connections. The inside diameter varies by type due to the different thickness of the walls. You won’t find type K copper under your sink or connected to other plumbing fixtures.

It's recommended for main water lines and underground installations because its thickness helps it withstand the pressure from backfilled earth in trenches. The rigid form of type k tubing is more likely to be used in commercial indoor applications and sprinkler systems. It's not however approved for use in natural gas applications because the gas environment can damage the joints of the pipes.

Type L Copper

Type L copper tubing is a large bore type of water supply pipe used in residential and commercial construction. It's manufactured from a combination of standard copper tubing and fittings combined with steel reinforcement. The steel reinforces the joints against corrosion, making it possible to have flexible connections without compromising the quality of the material that connects them together.

Type L Copper
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It can be used for interior plumbing, fire protection, and some HVAC applications. It's available in rigid and flexible forms and can be used with sweat, compression, and flare fittings. If your home is known to have water issues like hard water, type l copper is the best option because hard water will not wear through the thicker walls as easily as they do with type m pipe.

Marked with blue and equipped for interior water supply systems, hot water heating systems, and fire protection such as sprinkler systems, type l is the most commonly used of the copper pipe types. Flexible type l pipe can be used to repair or repair old water lines, although rigid tubing is more durable.

Type M Copper Pipe

Type M copper pipe has a wall thickness of 032 inches for a 3/4 diameter pipe, making it the thinner wall than both type k and l copper. Sold in both rigid and flexible forms, type m tubing is used most commonly for domestic water service and vacuum systems.

Type M Copper Pipe
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It can be used with sweat, compression, and flare fittings. This copper piping type is favored for residential work because of its relatively low price, a thinner wall means less copper and thus a lower price. Type m copper is not allowed by plumbing codes in all areas and applications. Always check with the local building authority for restrictions on its use.

Copper DWV Pipe

Copper pipe for plumbing drains and vents was used in many old homes and has been all but replaced with PVC or ABS plastic pipe in modern construction. It's suitable only for above-ground applications and has a low-pressure rating of 10 to 15 pounds per square inch, much lower than the water pressure of most municipal water supply systems.

Copper DWV Pipe
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Copper DWV comes in larger diameters than other types of copper and is distinguished by yellow markings. It also has thinner walls than other types of copper pipes. The thin walls on DWV copper can only withstand a maximum pressure rating of 15psi, hence the narrow range of use.

Uses Copper Piping for Home Piping Material

Alongside other materials such as steel and PVC, copper piping is also widely used as one of the home piping materials. All the pipe types are suitable for use as plumbing, but DWV may not be used for water supply pipes since it lacks pressure rating. Type k or green copper pipe is the only one suitable for burial and is often used to bring the water supply into a home.

Type m and l make up the water supply pipes in homes. Type l has a thicker wall and a higher pressure rating. Some local codes specify that only type l is allowed and that type m isn't allowed. The International Building Code allows both L and M and types K for use as water supply pipe.

FAQs on Types of Copper Piping

Should I use type L or type M copper pipe?

If you're looking for more strength and protection, use type L copper pipe, but for normal household plumbing, type M copper pipe is just fine.

What is DWV copper?

DWV copper tubing straight lengths are designed for use in drain waste vent systems.

Final Verdict on the Types of Copper Piping

There you have it. Copper piping is infinitely useful, but there are different types for specific uses.  Make sure you get one that fits your need without sacrificing too much money. Also, note that manufacturers make hard and soft copper for water supply plumbing.

Soft copper pipe bends easily without and is more properly called tubing. Copper piping is also the most expensive type of piping material available, so make sure you have a clear budget before making a purchase.


Kristina Perrin

Kristina Perrin

Kristina is an expert DIY home remodeler and mom to three. When she's not cooking or experimenting with new recipes, you can find her working on new home improvement projects or writing about her favorite kitchen appliances or DIY projects on Kitchen Infinity blog.

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