How to Connect Copper Pipe to PEX Pipe

Copper pipe is a popular option in plumbing due to its many benefits over other tubing. Plumbers can use it both for new construction projects and as an upgrade for existing copper pipes in homes.

However, connecting copper to pex requires special knowledge on how to do so correctly. There are a few options for joining these two different pipe materials together.

1. Threaded Adapter

PEX plumbing supply has gained in popularity among homeowners due to its long-term durability and affordability. Furthermore, it requires fewer fittings than copper, potentially leading to less risk of leaks or failures during installation and repair.

PEX piping offers several advantages over traditional copper, such as resistance to rust and corrosion, making it ideal for areas with hard water or other conditions where mineral buildup can occur. Furthermore, its lower temperature or freezing temperatures make it less likely to corrode or break, potentially saving you money in the long run.

If you need to convert copper pipe to PEX tube, there are several methods. One popular option is using a threaded adapter which can be found in many hardware stores. This adapter features male garden hose thread connection on one end and female pipe thread connection on the other.

Installing this type of connector couldn’t be simpler: just screw it onto the end of your copper pipe. Make sure you select a fitting that matches the outside diameter of your pipe, as this will create a watertight seal.

Once the threaded connection is secure, you can slide your PEX tubing onto the connector. Depending on its size, you may require either a clamp or crimp tool to complete the connection.

Another method for connecting PEX tubing is using a push-fit straight connector. These come in various sizes and require only that you measure the insertion depth of your copper pipe and mark it on the connector.

Insert the PEX tubing into the connector until it reaches this depth. Repeat until both ends of the copper pipe are connected to the connector.

When installing a tubing line, you can also use a copper stub-out to eliminate the need for a joint between the two tubes. This type of fitting can be concealed under an appliance such as under a sink or vanity cabinet.

2. Slip Adapter

PEX is the most common pipe material used in residential plumbing today, as it’s more cost-effective and simpler to install than copper. However, if you need to repair a section of copper that supplies fixtures or add an additional supply line, you’ll have to connect them together.

Thankfully, adapters make this connection simple. These female sweat adapters allow you to transition from copper to PEX pipe without needing solder. They’re suitable for various kinds of PEX fitting systems and there are plenty of them to choose from.

To attach an adapter to a PEX pipe, insert one end of the adapter into the pipe and push until you reach its depth marking on the connector. This will guarantee secure connection.

For a secure connection, you’ll need either a crimp ring or cinch clamp. While special tools for these purposes exist, an ordinary side cutter will suffice.

Before applying any fittings to copper pipe connecting it to PEX, make sure the pipe is free from dirt and debris. Doing this will guarantee a watertight seal.

Additionally, you’ll need a pair of gloves to protect yourself from hot copper leaks and keep your hands clean. Goggles can also shield your eyes from the intense glare from direct heat sources that could harm copper pieces.

Installing a crimp or cinch ring requires sliding it onto the end of PEX tubing and fitting over copper adapter with appropriate tool (a rotary tool equipped with a cutoff blade is ideal). Once in place, tighten with appropriate tool until tight.

Once the crimp or cinch ring is tightened, wrap a small amount of plumber’s tape around its threaded end for a watertight seal. Doing this will prevent copper pipe from stripping the threads on an adapter or damaging plastic material.

Once the copper adapter is secured to the copper pipe, it’s time to attach the PEX tube to its brass connector. A support sleeve should be used over both sides of both pipes before pushing them together for added support and prevent them from collapsing.

3. Solder-On Adapter

PEX pipe, also known as cross-linked polyethylene tubing, is a widely-used plumbing material for new construction and repairs due to its affordability, flexibility and durability in extreme temperatures.

Copper pipe has been a long-time go-to piping material for residential and commercial uses due to its lightweight nature, ease of workability and bio-static environment that prevents bacteria growth inside the pipes.

Corrosive resistance: this material resists reactions with chlorine, fluorine or other water contaminants. That makes it an ideal choice for residential and commercial projects exposed to acidic or hard-water conditions.

However, copper pipes tend to be more costly than PEX due to their higher quality source and need for processing and soldering in order to be usable in plumbing applications. This translates into a higher labor cost for plumbers who use copper pipes.

Fortunately, there are various methods for connecting PEX pipe to copper pipe. Some require special tools like a crimper, while others are easy enough for even the average homeowner to utilize.

One straightforward method is to solder a PEX adapter onto the end of a copper pipe. This simple method requires no special tools and takes minimal time.

Installing a solder-on adapter requires first cleaning the copper pipe and applying flux for added adhesion. Next, heat the seam where the pex fitting meets the copper pipe with a torch, then solder the copper pipe onto its adapter.

Once this is complete, wrap a bit of plumber’s tape around the threaded end to make it watertight. Finally, attach one end of PEX pipe to another side of the adapter, making sure they are flush with each other.

Another popular method for connecting copper pipe to PEX is installing a threaded female fitting on the end of the PEX pipe. These fittings are typically brass, but you may also find copper and pvc versions. These types of fittings are simpler to work with than crimp rings or push-fit connectors and come in various lengths and sizes to suit almost any project.

4. Push-In Fitting

Push-fit fittings offer a fast and cost-effective solution to connecting copper pipe to PEX pipe. As they require no special tools or crimping, installation is much simpler than with traditional soldered connections, saving time for DIYers who need an expeditious solution for simple plumbing jobs.

To make the connection, first cut away some copper pipe to make room for your new fitting. If this segment was also fed by fixture supply lines, remove those too so your PEX pipe can fit securely. Doing this creates a clean and straight connection and allows you to replace old copper fixtures with ones made with PEX pipe instead.

When cutting the pipe, make a clean and square cut with your cutter. Next, run a de-burring tool along the cut to smooth out any jagged edges. Doing this will guarantee an efficient connection with the fitting and prevent corrosion from forming in the pipe.

Next, insert the end of your copper tubing into a push-fit fitting. Be sure that it is inserted to the correct depth and mark this measurement with a marker so you can easily follow along when pushing it into the fitting.

John Guest fittings, for instance, come with nuts on their ends that must be hand-tightened to fully secure the connection. While this is generally a wise practice, it can be particularly challenging when positioning the fittings over sharply-cut pipe.

Once the connection is made, use a disconnect clip to release the locking mechanism on your fitting and take out the insert. This will make it easy to take out later if necessary.

Once again, use needlenose pliers to grasp the insert and pull gently past the o-ring until its retainer ring (steel ring with teeth) stops it. You may also re-insert the insert but this will reduce flow through the PEX tube.

Once the fitting has been reconnected to the copper pipe, switch off the water supply in order to avoid any damage during removal. You may also use a push-fit fitting removal tool – a horseshoe-shaped clip that fits over PEX pipe and presses against its release collar – which helps pull out copper pipe from its fitting.

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