Easy Steps On How To Connect Two Faucet Supply Lines And What Is The Best Type Of Connection

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If you have a leaky faucet line, then it will need to be replaced immediately. Typically, this is a relatively easy process that can be completed in a few minutes without the need to call out a plumber.

In this blog post, we will show our readers how to connect two faucet supply lines. We will cover the different types of connection methods and which is best.

The Best Way To Connect Two Faucet Supply Lines

Two Faucet Supply Lines

Faucet supply lines are made from several different types of materials and come in different lengths with different connectors for the attachment.

Some methods are better than others. Soldering two pipes together will require special equipment that not everybody will have, not to mention the skills.

In our opinion, compression fittings are the perfect solution as they are not only the easiest connector to use but are very safe as there is no soldering or complicated processes involved in connecting the two pipes. Additionally, a compression fitting will allow you to join two pipes of different materials together

Typically, a compression faucet fitting will allow you to join two pipes of different materials together with a water-tight seal. You can twist a screw in the center to either open or close the water flow. This makes it especially convenient if you need to work specifically in the sink and still need the water running in other parts of the bathroom.

Easy Steps On How To Connect Two Faucet Supply Lines Using Compression Fittings

Highcraft CNCT27116-OM-2 Braided Faucet Connector 16" Long, 1/2"

Step 1 : Turn Water Off

When it comes to bathroom jobs the first thing to almost always do is turn the water supply off so that you can work without flooding your entire house or at least getting wet.

Step 2 : Measure the Length of the Pipe Required

If you are installing new faucets then you will already have supply lines included however, you will need to make sure they reach the shutoff valve and have enough length to securely thread onto the tube.

If your supply line is not long enough then you will need to measure from the thread of the faucet to the thread of the shutoff valve and be sure to add 3 to 4 inches to allow for bends.

Step 3.1 : Connecting Compression Fitting For Flexible Pipes

Once the faucet is installed place a rubber/silicone sleeve or olive over the tube and tighten the nut, you can use Teflon tape on the pipe for added security giving you a better seal. Work the pipe around the space and then slide the seal or olive on the opposite side of the pipe and attach the compression fitting connecting the pipe to the shutoff valve.

Step 3.2 : Connecting Compression Fitting For Hard Plastic or Metal Pipes

The process here is essentially the same but you will need to create bends feeding the pipe through the available spaces. Attach the pipe to the faucet using Teflon tape and a metal or plastic sleeve depending on what pipe material you are using, before tightening the nut for a waterproof tight seal. Use a compression fitting to join the 2 pipes together.

Top Tip: When hot water runs the pipe will heat up quite considerably. Make sure there are 6 -8 inches of space between the hot and cold water supply pipes.

How to Connect Two Faucet Supply Lines With a Solder

In most cases, a compression fitting will suffice in connecting two pipes together however, there are certain situations where the trusty compression fitting will simply not do. The perfect example of this is when installing piping for central heating radiators in a home.

Step 1: Safety Equipment

Safety equipment such as heatproof gloves and goggles are essential when using soldering irons so make sure you have these before starting this project.

Step 2: Turn Off Water

As it is with pretty much any plumbing job, you will need to turn off the water from the mains to be able to connect the faucet supply lines.

Step 3: Sanding The Pipes

Prepare the pipes for the soldering process by sanding the exterior ends that will penetrate the joining pipe with some sandpaper and then using a small metal wire brush clean the interior of the fitting that is used to join the two ends. These fittings generally come already clean but you will need to rough up the surface for the soldering process.

Step 4: Flux The Pipe

To ensure a good soldering joint, the pipe will need to be properly cleaned. Brush flux on the end of the copper pipe and on the inside of the fitting, to remove any oxidation or impurities that may have accumulated on the surface.

Step 5: Install Pipe Inside Fitting And Solder

Insert the copper pipe into the fitting and ensure it fits well before starting the soldering part. Take your flame and heat the portion of the pipe where the filler needs to pack into, in order to create that perfect seal.

You should use lead-free filler for the soldering because it is in an area where you or your children can potentially touch it.

Ensure the entire joint has been covered with the filler and you have gone all the way around the pipe. If you see gaps in the joint, apply flux again and reheat and solder with the filler.

Top Tip: Remember to heat and solder the bottom part of the fitting joint before the top. If you start at the top the hot filler liquid will flow down and because the bottom part will be cool it won’t stick and either drip on the floor or solidify at the bottom of the joint.

Step 6: Wait to Cool

Once the pipe has cooled down apply a generous layer of flux and clean the pipe with a cloth removing any burnt residue from the pipe. Make sure to wipe off the flux otherwise, it will eat away at the joint and pipe and create gaps and leaks.

Step 7 : Turn on the Water

Once you have finished cleaning the pipe of any excess flux, turn the water on and check if there are any leaks. If you see any water leaking from the joint fixture then you will have to repeat the process.

Different Types of Faucet Supply Lines

There are different types of faucet supply line pipes, and they all use unique compression fittings. It is a good idea to check under the bathroom or kitchen sink to familiarize yourself with the type of tube you have as well as the length and the size of the fittings of the tube that you require. Once you know the size and fittings it will make picking the right tube much easier.

Below are some of the different tubes available.

Braided nylon flexible tube

Braided nylon flexible tube

This is essentially a flexible PVC tube that is reinforced with braided nylon giving it extra strength, making it very durable and perfect for both hot and cold water.

They are generally made in very long lengths and can be cut to any required size. Clips that can be tightened sit on the ends to attach to faucets or other devices.

Stainless steel braided flexible tube

Stainless steel braided flexible tube

Similar to the nylon braided PVC tubes the core in these tubes is the same PVC solid pipe, however, the exterior is encased in braided stainless steel.

They are typically the most expensive option but are a lot stronger, more durable, and can withstand higher temperatures resulting in longer than their nylon counterparts.

Polymer-coated flexible pipe

Polymer-coated flexible pipe

The polymer-coated pipe is very similar in look when compared to the steel braided pipe and is often used in bathrooms and kitchens for the hot and cold water supply.

These pipes tend to be cheaper compared to steel braided tubes but are just as strong and durable. Due to the sleek look of these pipes, they are often used in situations when pipes have to be exposed.

PVC flexible pipe

ealproof Flexible PVC Pipe 2 Inch Dia Hose 25 FT Length, Black Tubing, Schedule 40

PVC flexible pipe is the most basic pipe from this range. These pipes have a central core made of PVC that is encased in vinyl. They are not typically very strong and consequently should not be used for hot water as they can expand and crack over time.

In spite of the fact they are cheap, you should try and get a better quality pipe that will last you longer and give you fewer problems in the long run.

Flexible copper supply pipe

MuHize 1/4" Brake Line Tubing Kit - 25 Ft. of 1/4 Flexible Copper Coated Brake Line Tube Roll 25 ft

Flexible copper pipes are usually used for outdoor grills, spas, and gas fireplaces, however, due to their flexibility and non-corrosive properties, more and more people are using them in the kitchen and bathroom for the water supply lines.

FAQS Frequently Asked Questions

How long does flexible copper pipe last?

Copper is one of the most durable metals when it comes to kitchens and bathrooms. It is widely used in the home from pots, pans, and ladles to bathtubs, fixtures, and piping of course. It is an extremely durable metal and is rust-proof and noncorrosive and pipes constructed of copper will generally last 80+ years.

Why is soldering plumbing illegal?

Soldering plumbing is illegal in pipes that are used for water that humans consume because of the lead that is present in the flux needed in the soldering process. The Safe Drinking Water act that was amended In 1986 by Congress to reflect these new restrictions.

What causes a Flexi pipe to burst?

The main cause for flexible pipes to burst is if they expand due to excessive pressure, generally, the steel or nylon braiding will not allow this but if the braiding is compromised in any way then the PVC pipe inside can swell up and burst.

Can you use old faucets with new supply lines?

Yes if you have vintage faucets or just love your current faucets but need to change the supply lines then that is absolutely possible. Take the old supply lines to your hardware store with the attachments and get replacements so that they fit your faucets exactly.

Can you use old supply lines with a new faucet?

You want to change your faucets but your water supply lines are in good condition. There is no need to spend extra time and money fitting new supply lines simply buy an adapter that connects your new faucets to your pipes.

Should I use plumbers’ tape on a faucet?

Wrapping the plumber’s tape on the thread and tightening the screw will ensure a leak-proof seal that will last you years.


The above article has given you a good idea of how to connect two faucet supply lines without having to employ an expensive plumber. Always remember to follow the instructions that come with any of the fixtures that you are installing, from the pipes to the faucets.

Oh, and don’t forget to turn the water off first otherwise, you could be spending a considerable amount of time mopping up before you even start the project.

Installing faucet supply lines is a relatively easy job and can be quite rewarding when you are done. So we would like to thank you for reading the article and now it’s time to take action.

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